Crispy Onion Chicken Sandwich

Featured in: Family Dinners

This show-stopping sandwich combines buttermilk-marinated fried chicken thighs with a golden, crispy coating. The real star is the mound of fried onion strings piled high for maximum crunch. Creamy garlic aioli brings everything together beautifully. Toast your brioche buns until buttery and golden, then assemble with optional lettuce for freshness. The whole process takes about 50 minutes, making it perfect for a special lunch or dinner.

Updated on Sun, 18 Jan 2026 14:06:00 GMT
Golden-brown, crispy fried chicken thighs piled high on a toasted brioche bun, generously topped with crunchy fried onions and creamy aioli. Save
Golden-brown, crispy fried chicken thighs piled high on a toasted brioche bun, generously topped with crunchy fried onions and creamy aioli. | griddleglory.com

My kitchen smelled like a roadside diner for three days straight, and I didn't mind one bit. I'd been chasing the perfect fried chicken sandwich for months, trying different marinades and coatings, until one Saturday I decided to pile crispy fried onions on top. The crunch echoed through the room with every bite. That's when I knew I'd finally cracked it.

I made this for my brother's birthday last spring, and he ate two sandwiches back to back without saying a word. When he finally looked up, he just pointed at the platter and nodded. My sister-in-law laughed and told me I'd ruined every other chicken sandwich for him. I took that as the highest compliment.

Ingredients

  • Boneless, skinless chicken thighs: Thighs stay juicier than breasts and handle the marinade beautifully, plus they fry up with more flavor and forgive a minute or two of extra cooking time.
  • Buttermilk: The acidity tenderizes the meat while adding a subtle tang that balances the richness of frying, and it helps the breading stick like glue.
  • Garlic powder and paprika: These season the marinade from the inside out, building flavor layers that plain salt can't match.
  • All-purpose flour and cornstarch: The cornstarch makes the coating extra crispy and light, creating that audible crunch when you bite down.
  • Smoked paprika: It adds a smoky depth to the breading that makes people ask what your secret is.
  • Yellow onion: Thin slices turn into sweet, shattering crisps that add texture and a slight caramelized sweetness.
  • Mayonnaise: The base of the aioli, it clings to the chicken and bun while carrying the garlic and lemon flavors everywhere they need to go.
  • Garlic clove: Fresh garlic in the aioli gives a sharp, bright punch that jarred garlic just can't replicate.
  • Lemon juice: A splash cuts through the fat and wakes up every other flavor on the sandwich.
  • Dijon mustard: Just half a teaspoon adds complexity and a tiny bit of heat that sneaks up on you.
  • Brioche buns: Soft, slightly sweet, and sturdy enough to hold all that chicken and onion without falling apart halfway through.
  • Vegetable oil: Neutral flavor and a high smoke point make it perfect for frying without any burnt or off tastes.

Instructions

Marinate the chicken:
Whisk the buttermilk with garlic powder, paprika, salt, and pepper until it's smooth and fragrant. Submerge the chicken thighs completely, making sure every inch is coated, then cover and let them rest in the fridge for at least thirty minutes so the flavors soak in deep.
Prepare the breading station:
Combine the flour, cornstarch, smoked paprika, salt, and pepper in a shallow dish, mixing well so the spices are evenly distributed. This dry mixture will cling to the buttermilk-coated chicken and create that satisfying crunchy shell.
Coat the onions:
Toss the thinly sliced onions with flour, salt, and pepper until each piece is lightly dusted. The coating should be thin but complete, which helps them fry up crisp instead of soggy.
Fry the onions:
Heat about an inch of oil in a large skillet to 350 degrees, then drop in the onions in small batches so they don't clump together. Fry for two to three minutes until they're golden and crispy, then drain them on paper towels and resist the urge to snack on them all before assembly.
Bread and fry the chicken:
Lift each thigh from the marinade, let the excess drip off, then press it firmly into the breading mixture on both sides. Slide the coated chicken into the hot oil and fry for five to seven minutes per side until the crust is deep golden and the internal temperature hits 165 degrees.
Make the aioli:
Stir together the mayonnaise, minced garlic, lemon juice, Dijon, salt, and pepper in a small bowl until smooth. Taste it and adjust the seasoning, because this sauce will be the glue that holds every flavor together.
Toast the buns:
Butter the cut sides of the brioche buns and press them into a hot skillet until they're golden and slightly crisp. This step adds texture and keeps the buns from getting soggy under all that juicy chicken.
Assemble the sandwiches:
Spread aioli generously on both halves of each bun, layer on lettuce if you want, then stack a fried chicken thigh and pile on a big handful of crispy onions. Press the top bun down gently and get ready for the crunch.
A fully assembled Crispy Onion Chicken Sandwich on a plate, ready to be enjoyed with lettuce and extra onions peeking out. Save
A fully assembled Crispy Onion Chicken Sandwich on a plate, ready to be enjoyed with lettuce and extra onions peeking out. | griddleglory.com

The first time I served these at a backyard cookout, my neighbor asked if I'd ordered them from a restaurant. I handed him the recipe on a napkin, and now he texts me every few weeks to tell me he made them again. It's become our thing, and I love knowing this sandwich is making the rounds in other kitchens.

Getting the Marinade Right

Buttermilk isn't just a tangy bath, it's a tenderizer that breaks down the proteins in the chicken so every bite is soft and juicy. I learned this after trying a plain milk marinade once and ending up with chicken that was fine but not memorable. The acidity matters, and if you don't have buttermilk, you can make a quick substitute by stirring a tablespoon of lemon juice or vinegar into regular milk and letting it sit for five minutes. The paprika and garlic powder in the marinade also start building flavor from the inside, which means you're not relying only on the breading to do all the work.

Mastering the Fry

I used to think frying was all about guessing and hoping, until I bought a cheap thermometer and everything changed. Keeping the oil at a steady 350 degrees is the difference between golden, crispy chicken and pale, greasy chicken that tastes heavy. If the oil is too hot, the outside burns before the inside cooks through. If it's too cool, the breading soaks up oil like a sponge. I also learned to fry in batches and give the oil time to come back up to temperature between them, which means patience but perfect results every time.

Serving and Storing

These sandwiches are best eaten hot and fresh, right after assembly when the onions are still crunchy and the chicken is steaming. If you need to make them ahead, fry the chicken and onions, then keep them warm in a low oven on a wire rack until you're ready to build the sandwiches. Leftover fried chicken keeps in the fridge for up to two days and reheats well in a 375-degree oven for about ten minutes, though the crust won't be quite as crispy as it was fresh.

  • Serve with dill pickles or a tangy coleslaw on the side to balance the richness.
  • If you want extra heat, stir hot sauce or a pinch of cayenne into the aioli or the breading.
  • These pair beautifully with crispy fries, potato wedges, or even a simple green salad.
Homemade Crispy Onion Chicken Sandwich stacked with juicy buttermilk chicken, crispy onions, and creamy aioli, served on a toasted brioche bun. Save
Homemade Crispy Onion Chicken Sandwich stacked with juicy buttermilk chicken, crispy onions, and creamy aioli, served on a toasted brioche bun. | griddleglory.com

This sandwich has earned a permanent spot in my weekend cooking rotation, and I hope it does the same for you. There's something deeply satisfying about biting through that crispy coating into tender, juicy chicken with all those sweet, crunchy onions on top.

Cooking Questions

Can I use chicken breasts instead of thighs?

Yes, chicken breasts work well as a substitute. They cook faster, so reduce the frying time to 4-6 minutes per side. Thighs stay juicier and more forgiving, but breasts will still deliver excellent results.

How long can I marinate the chicken?

Marinate for at least 30 minutes, but overnight produces the most tender, flavorful chicken. The buttermilk's acidity breaks down the protein fibers, keeping the meat moist during frying.

What's the best way to keep the onions crispy?

Fry the onions first and drain them well on paper towels. Assemble the sandwich just before serving so the onions don't absorb moisture from the aioli and lettuce.

Can I make the aioli ahead of time?

Absolutely. The aioli keeps refrigerated for up to 3 days. Prepare it while the chicken marinates to save time during assembly.

What oil should I use for frying?

Use vegetable, canola, or peanut oil—any neutral-flavored oil with a high smoke point around 350-400°F. Avoid olive oil, which has a lower smoke point and would overpower the delicate flavors.

How do I know when the chicken is fully cooked?

The internal temperature should reach 165°F (74°C) at the thickest part. Alternatively, pierce the meat—juices should run clear with no pink. A meat thermometer ensures perfect results every time.

Crispy Onion Chicken Sandwich

Juicy fried chicken, crunchy onions, and garlic aioli layered on soft brioche for the ultimate sandwich experience.

Prep duration
25 min
Cook duration
25 min
Complete duration
50 min
Created by Sarah Collins


Skill level Medium

Heritage American

Output 4 Portions

Nutrition specifications None specified

Components

Chicken & Marinade

01 4 boneless, skinless chicken thighs
02 1 cup buttermilk
03 1 teaspoon garlic powder
04 1 teaspoon paprika
05 ½ teaspoon salt
06 ½ teaspoon black pepper

Breading

01 1 cup all-purpose flour
02 ½ cup cornstarch
03 1 teaspoon smoked paprika
04 1 teaspoon salt
05 ½ teaspoon ground black pepper

Crispy Onions

01 1 large yellow onion, thinly sliced
02 ½ cup all-purpose flour
03 ½ teaspoon salt
04 ½ teaspoon black pepper
05 Vegetable oil for frying

Aioli

01 ½ cup mayonnaise
02 1 large garlic clove, minced
03 1 tablespoon fresh lemon juice
04 ½ teaspoon Dijon mustard
05 Salt and pepper to taste

Assembly

01 4 brioche buns, sliced
02 Butter for toasting buns, optional
03 Lettuce leaves, optional

Directions

Phase 01

Prepare buttermilk marinade: Whisk together buttermilk, garlic powder, paprika, salt, and black pepper in a bowl. Add chicken thighs, ensuring complete coating. Cover and refrigerate for at least 30 minutes or up to 4 hours.

Phase 02

Combine breading mixture: In a shallow dish, mix all-purpose flour, cornstarch, smoked paprika, salt, and black pepper thoroughly.

Phase 03

Coat onion slices: In a separate bowl, toss sliced onions with flour, salt, and black pepper until evenly coated.

Phase 04

Fry crispy onions: Heat 1 inch of vegetable oil in a large skillet to 350°F. Fry onions in batches until golden and crisp, approximately 2–3 minutes per batch. Transfer to paper towels to drain.

Phase 05

Bread and fry chicken: Remove chicken from marinade, allowing excess buttermilk to drip away. Dredge each thigh in the breading mixture, pressing firmly to adhere. Fry in the same hot oil for 5–7 minutes per side until cooked through and golden brown. Place on a wire rack or paper towels to drain.

Phase 06

Prepare garlic aioli: Combine mayonnaise, minced garlic, lemon juice, Dijon mustard, salt, and pepper in a small bowl. Mix until smooth.

Phase 07

Toast brioche buns: Optional step: Butter brioche buns and toast in a skillet until golden brown.

Phase 08

Assemble sandwiches: Spread aioli on both halves of each brioche bun. Layer with lettuce if desired, top with fried chicken, add a generous portion of crispy onions, and cap with the top bun.

Necessary tools

  • Mixing bowls
  • Large skillet or deep fryer
  • Tongs
  • Wire rack or paper towels
  • Knife and cutting board

Allergy details

Review each component for potential allergens and seek professional healthcare advice if you're uncertain.
  • Contains eggs from mayonnaise
  • Contains wheat from all-purpose flour and brioche buns
  • Contains milk from buttermilk and butter
  • Contains mustard from Dijon mustard in aioli
  • May contain soy or other allergens in brioche buns—verify product labels

Nutritional information (per portion)

These values are provided as a general guide only and aren't intended to replace professional medical guidance.
  • Energy: 670
  • Fats: 32 g
  • Carbohydrates: 61 g
  • Proteins: 32 g