Crispy Onion Chicken Sandwich (Printable)

Buttermilk-marinated fried chicken topped with crispy onions and garlic aioli on a toasted 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 fresh 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 together buttermilk, garlic powder, paprika, salt, and black pepper in a bowl. Add chicken thighs ensuring full coating. Cover and refrigerate for at least 30 minutes or up to 4 hours.
02 - In a shallow dish, combine flour, cornstarch, smoked paprika, salt, and black pepper. Set aside.
03 - Toss sliced onions with flour, salt, and black pepper in a separate bowl until well coated.
04 - Heat 1 inch of vegetable oil in a large skillet to 350°F. Fry onions in batches for 2–3 minutes per batch until golden and crisp. Drain on paper towels.
05 - Remove chicken from marinade, allowing excess buttermilk to drip off. Dredge each thigh in the breading mixture, pressing gently to adhere.
06 - Fry chicken in the same hot oil for 5–7 minutes per side until cooked through and golden brown. Transfer to a wire rack or paper towels to drain.
07 - Combine mayonnaise, minced garlic, lemon juice, Dijon mustard, salt, and pepper in a small bowl.
08 - Butter brioche buns and toast in a skillet until golden, approximately 2 minutes per side.
09 - Spread aioli on both sides of each bun. Layer with lettuce if desired, fried chicken thigh, generous amount of crispy onions, and close with top bun.

# Expert Suggestions:

01 -
  • The crispy onions add a texture and sweetness that store bought toppings just can't match.
  • Buttermilk keeps the chicken unbelievably tender even after frying.
  • The garlic aioli ties everything together without overpowering the other flavors.
  • It feels like a restaurant splurge but costs a fraction and tastes better.
02 -
  • Don't skip the cornstarch in the breading, it's what makes the coating stay crispy instead of going soft.
  • Let the chicken rest on a wire rack after frying instead of paper towels so the bottom doesn't steam and lose its crunch.
  • Fry the onions in small batches or they'll drop the oil temperature and turn greasy instead of crisp.
03 -
  • Press the chicken firmly into the breading and let it sit for a minute before frying so the coating sticks better.
  • Use a slotted spoon or spider strainer to turn the chicken and onions so you don't disturb the oil too much.
  • If the garlic in the aioli tastes too sharp, let it sit for 10 minutes before using, the flavors will mellow.
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