Crispy Onion Chicken Sandwich (Printable)

Buttermilk-marinated fried chicken topped with crispy onions and garlic aioli on brioche buns.

# Required Ingredients:

→ Chicken & Marinade

01 - 4 boneless, skinless chicken thighs
02 - 1 cup buttermilk
03 - 1 teaspoon garlic powder
04 - 1 teaspoon paprika
05 - 0.5 teaspoon salt
06 - 0.5 teaspoon black pepper

→ Breading

07 - 1 cup all-purpose flour
08 - 0.5 cup cornstarch
09 - 1 teaspoon smoked paprika
10 - 1 teaspoon salt
11 - 0.5 teaspoon ground black pepper

→ Crispy Onions

12 - 1 large yellow onion, thinly sliced
13 - 0.5 cup all-purpose flour
14 - 0.5 teaspoon salt
15 - 0.5 teaspoon black pepper
16 - Vegetable oil for frying

→ Aioli

17 - 0.5 cup mayonnaise
18 - 1 large garlic clove, minced
19 - 1 tablespoon fresh lemon juice
20 - 0.5 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

# Preparation Steps:

01 - In a mixing bowl, whisk together buttermilk, garlic powder, paprika, salt, and black pepper. Add chicken thighs, ensuring complete coverage. Cover and refrigerate for minimum 30 minutes, up to 4 hours.
02 - In a shallow dish, combine flour, cornstarch, smoked paprika, salt, and black pepper. Set aside for dredging station.
03 - In a separate bowl, toss sliced onions with flour, salt, and black pepper until evenly 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 crisp. Transfer to paper towels to drain.
05 - Remove chicken from marinade, allowing excess liquid to drip off. Dredge each thigh thoroughly in breading mixture, pressing gently to ensure adhesion.
06 - Carefully place breaded chicken into hot oil. Fry 5-7 minutes per side until internal temperature reaches 165°F and exterior is golden brown. Transfer to wire rack to drain.
07 - In a small bowl, whisk together mayonnaise, minced garlic, lemon juice, Dijon mustard, salt, and pepper until smooth and well combined.
08 - Optional step: Butter brioche buns and toast in skillet over medium heat until golden brown on both sides.
09 - Spread aioli on both sides of each toasted bun. Layer with lettuce if desired, top with fried chicken thigh, generous mound of crispy onions, and close with top bun.

# Expert Suggestions:

01 -
  • The buttermilk marinade keeps the chicken so tender you'll wonder why you ever skipped that step before.
  • Crispy fried onions add a texture that makes every bite feel like a celebration.
  • The garlic aioli ties everything together with a creamy tang that balances the richness perfectly.
  • It comes together in under an hour but tastes like you spent all day in the kitchen.
02 -
  • Don't skip the marinating time; even 30 minutes makes a noticeable difference in tenderness and flavor.
  • Keep the oil temperature steady at 350°F; too hot and the coating burns before the chicken cooks through, too cool and it gets greasy.
  • Fry the onions in small batches so they crisp evenly and don't steam each other.
  • Let the fried chicken rest on a wire rack instead of paper towels to keep the bottom from getting soggy.
03 -
  • Press the breading onto the chicken firmly with your hands to create a thicker, crunchier crust.
  • Use a thermometer to monitor oil temperature; consistency is the key to perfectly fried chicken every time.
  • Let the chicken rest for a few minutes after frying so the juices redistribute and every bite stays moist.
  • Toast the buns just before assembling to add texture and prevent them from getting soggy too quickly.
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