Put about 1/2 inch of oil in a large deep skillet. Heat to 350 F
Slice the chicken breasts in half crosswise to make 4 equal-sized cutlets.
Put the buttermilk and hot sauce in a shallow wide bowl.
Combine the flour, pepper, salt, garlic powder, onion powder, sage, and thyme in a bowl. Blend well.
Dip a chicken cutlet in the flour mixture, turning to coat lightly. Next dip the cutlet in the buttermilk and hot sauce mixture, turning to coat both sides. Again dip in the flour mixture to coat thoroughly. Repeat with the remaining chicken cutlets.
Put the chicken cutlets in the hot oil and fry for about 3 to 4 minutes on each side, or until the chicken is cooked through.
Meanwhile, combine the mayonnaise and Sriracha sauce, if using. Blend well.
Transfer the cooked chicken pieces to a cooling rack set in a pan or paper towels to drain. Sprinkle lightly with salt and pepper.
Arrange chicken on toasted buns with lettuce slices, pickles, and desired toppings, along with Sriracha mayonnaise or sauce of your choice.
