Place the boneless chicken breasts in a resealable bag. Pour the buttermilk over them, ensuring they’re well coated. Seal the bag, squeeze out excess air, and refrigerate for at least 30 minutes.

In a wide bowl, mix together the flour, cornstarch, garlic powder, onion powder, paprika, cayenne, salt, and black pepper.

Remove chicken from the fridge, let excess buttermilk drip off, and dredge each piece in the flour mixture.

Heat oil in a large skillet over medium heat until shimmering. Cook the chicken for about 5 minutes per side until it’s cooked through and golden brown.

Toss the cooked chicken in the buffalo sauce until they’re well coated.

In a mixing bowl, combine the green and purple cabbage, carrots, parsley, dill, mayonnaise, sour cream, lemon juice, and apple cider vinegar. Stir until combined.

Toast the brioche buns lightly. On the bottom bun, spread a layer of ranch slaw, add the buffalo chicken, and top with more slaw if desired. Finally, add the top bun.