Crispy Onion Chicken Sandwich (Print Version)

Juicy fried chicken, crispy onions, and creamy aioli come together on a soft brioche bun.

# What You’ll Need:

→ 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

07 - 1 cup all-purpose flour
08 - ½ cup cornstarch
09 - 1 teaspoon smoked paprika
10 - 1 teaspoon salt
11 - ½ teaspoon ground black pepper

→ Crispy Onions

12 - 1 large yellow onion, thinly sliced
13 - ½ cup all-purpose flour
14 - ½ teaspoon salt
15 - ½ teaspoon black pepper
16 - Vegetable oil, for frying

→ Aioli

17 - ½ cup mayonnaise
18 - 1 large garlic clove, minced
19 - 1 tablespoon lemon juice
20 - ½ teaspoon Dijon mustard
21 - Salt and pepper, to taste

→ Assembly

22 - 4 brioche buns, sliced
23 - Butter, for toasting buns (optional)
24 - Lettuce leaves (optional)

# How to Make It:

01 - Whisk buttermilk, garlic powder, paprika, salt, and black pepper in a bowl. Add chicken thighs and ensure full coating. Cover and refrigerate for at least 30 minutes up to 4 hours.
02 - Combine all-purpose flour, cornstarch, smoked paprika, salt, and black pepper in a shallow dish.
03 - Toss sliced onions with flour, salt, and black pepper until evenly coated.
04 - Heat vegetable oil to 350°F (175°C) with 1-inch depth in a large skillet. Fry onions in batches for 2 to 3 minutes per batch until golden and crisp. Drain on paper towels.
05 - Remove chicken from marinade and let excess drip off. Dredge each thigh thoroughly in the breading mixture, pressing to adhere.
06 - Using the same hot oil, fry chicken thighs for 5 to 7 minutes per side until golden brown and cooked through. Drain on wire rack or paper towels.
07 - Mix mayonnaise, minced garlic, lemon juice, Dijon mustard, salt, and pepper in a small bowl until combined.
08 - Butter brioche buns lightly and toast in a skillet until golden brown.
09 - Spread aioli on both bun halves. Add lettuce if desired, place fried chicken, pile crispy onions generously, and top with the bun.

# Additional Tips::

01 -
  • The contrast of textures—crispy skin, tender chicken, crunchy onions, soft brioche—all in one bite is genuinely addictive.
  • Buttermilk marinating makes the chicken impossibly juicy, and you'll taste the difference the moment you bite through.
  • It looks fancy enough to impress guests but comes together faster than you'd expect for something this good.
02 -
  • Temperature control is everything: too hot and your breading burns before the chicken cooks through; too cool and you get greasy, soggy coating instead of crispy.
  • Crispy onions go soft quickly once they hit moisture, so assemble these sandwiches close to when you finish frying—they're best eaten within minutes of coming together.
  • Excess buttermilk clinging to the chicken before breading causes the coating to separate during frying; let it drip off properly and press the breading on firmly.
03 -
  • Use a meat thermometer to know for certain when your chicken is done; perfectly fried chicken is 165°F inside and golden outside, not a guessing game.
  • If your oil temperature drops when you add chicken, wait for it to return to 350°F before frying the next batch—this makes the difference between crispy and greasy.
  • Fried onions lose their crispness minutes after they cool, so fry them just before you fry the chicken so everything comes together while textures are at their peak.
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