Crispy Onion Chicken Sandwich (Printable)

Buttermilk-marinated fried chicken layered with crispy fried onions, creamy garlic aioli, and soft brioche for an irresistible sandwich.

# What You Need:

→ Chicken & Marinade

01 - 4 boneless, skinless chicken thighs
02 - 1 cup buttermilk
03 - 1 teaspoon garlic powder
04 - 1 teaspoon paprika
05 - 1/2 teaspoon salt
06 - 1/2 teaspoon black pepper

→ Breading

07 - 1 cup all-purpose flour
08 - 1/2 cup cornstarch
09 - 1 teaspoon smoked paprika
10 - 1 teaspoon salt
11 - 1/2 teaspoon ground black pepper

→ Crispy Onions

12 - 1 large yellow onion, thinly sliced
13 - 1/2 cup all-purpose flour
14 - 1/2 teaspoon salt
15 - 1/2 teaspoon black pepper
16 - Vegetable oil for frying

→ Aioli

17 - 1/2 cup mayonnaise
18 - 1 large garlic clove, minced
19 - 1 tablespoon fresh lemon juice
20 - 1/2 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 - In a mixing bowl, whisk together buttermilk, garlic powder, paprika, salt, and black pepper. Add chicken thighs, ensuring complete 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 - In a separate bowl, toss sliced onions with flour, salt, and black pepper until thoroughly coated.
04 - Heat 1 inch of vegetable oil in a large skillet to 350°F. Working in batches, fry onions for 2-3 minutes per batch until golden and crispy. Drain on paper towels.
05 - Remove chicken from marinade, allowing excess buttermilk to drip off. Dredge each thigh in the breading mixture, pressing firmly to ensure adhesion.
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 excess oil.
07 - In a small bowl, combine mayonnaise, minced garlic, lemon juice, Dijon mustard, salt, and pepper. Mix until smooth.
08 - Optional: Butter brioche buns and toast in a skillet over medium heat until golden brown.
09 - Spread aioli on both sides of each bun. Layer with lettuce if desired, followed by fried chicken, a generous portion of crispy onions, and top with bun half.

# Expert Hints:

01 -
  • The buttermilk marinade keeps the chicken so tender you can cut it with the edge of your bun.
  • Crispy onions add a sweet crunch that makes every bite feel like a celebration.
  • The aioli is tangy and creamy, pulling everything together without overpowering the chicken.
  • Its impressive enough for guests but forgiving enough for a weeknight once you get the hang of it.
02 -
  • Dont skip the marinating time, I tried it once in a rush and the chicken was noticeably less tender.
  • Keep your oil temperature steady at 350 degrees F, too hot and the breading burns before the chicken cooks through, too cool and it gets greasy.
  • Press the breading onto the chicken firmly, loose coating will fall off in the oil and leave you with bare spots.
  • Make extra crispy onions, they disappear faster than you think and theyre impossible to resist.
03 -
  • Use a thermometer to check your oil temperature, guessing leads to uneven frying and greasy chicken.
  • Let the fried chicken rest on a wire rack instead of paper towels, it keeps the bottom from getting soggy.
  • Double the onion recipe, you will regret not having extras.
  • If your breading clumps, whisk a tablespoon of the buttermilk marinade into the flour mixture to create little crispy bits.
Go Back