Make the quick yuzu pickles first so flavors can develop. In a small bowl combine rice vinegar, water, sugar, kosher salt, and yuzu juice and zest. Whisk until sugar and salt dissolve.

Place the cucumber slices in a jar or shallow bowl and pour the pickling liquid over them, pressing to submerge. Refrigerate at least 30 minutes (up to 24 hours). Drain before assembling sandwich.

Cherry Pepper Aioli

In a small bowl combine mayonnaise, chopped pickled cherry peppers, grated garlic, lemon juice, smoked paprika, salt, and black pepper. Stir until smooth and taste; adjust salt or lemon as needed.

Cover and refrigerate the aioli for at least 15 minutes to let flavors meld. Leave chilled until assembly.

Fried Chicken

Brine/Marinate

Place trimmed chicken thighs in a shallow dish or zip-top bag. Mix buttermilk with hot sauce and 1/2 tsp kosher salt and pour over chicken. Marinate in the refrigerator for at least 1 hour, ideally 4 hours or up to overnight.

Dredge

When ready to fry, whisk together flour, cornstarch, baking powder, garlic powder, onion powder, smoked paprika, remaining 1 tsp kosher salt, and black pepper in a large bowl or shallow pan. Remove chicken from buttermilk, letting excess drip off, and dredge thoroughly in the flour mixture, pressing to adhere a thick coating. For an extra-crisp crust, double-dredge: after first coating, dip quickly back into buttermilk then again into flour mixture.

Heat oil

Pour vegetable oil into a heavy 10–12" skillet or Dutch oven to reach about 1" depth. Heat over medium-high until oil reaches 350°F (175°C) on a thermometer. If you don't have a thermometer, a small piece of bread should brown in ~45 seconds.

Fry

Carefully add chicken pieces (do not overcrowd) and fry until golden brown and internal temperature reaches 165°F (74°C), about 5–7 minutes per side depending on thickness. Maintain oil temperature around 325–350°F by adjusting heat. Transfer cooked chicken to a wire rack set over a sheet pan and rest for 5 minutes; this preserves crispness.

Assembly & Toasting

Lightly butter the cut sides of the buns. Heat a skillet over medium heat and toast buttered sides until golden, about 1–2 minutes. Alternatively, use a griddle or broiler on low for a brief toast.

Spread about 1 tablespoon of cherry pepper aioli on the bottom bun. Place a leaf of iceberg lettuce on the aioli to act as a moisture barrier.

Place the fried chicken on top of the lettuce. Spoon 2–3 tablespoons of drained yuzu pickles over the chicken (more if you like a brighter acidic hit). Add a drizzle (about 1 tsp) of remaining aioli on the top bun if desired.

Close the sandwich, press gently, slice in half if sharing, and serve immediately while chicken is hot and crisp.