First, butterfly then brine the chicken breast. Remove the chicken breast from the fridge and pat dry with paper towels. Use a sharp knife to butterfly the breast — place your hand on the breast and slice through it starting at the thickest part to slice it in half horizontally. Mix up the brine by combine the buttermilk, soy sauce, 1 tablespoon Red Tuxedo, garlic, and scallion. Add the chicken breast pieces and brine for at least 6 hours or overnight.
Before you fry the chicken breasts, make a quick slaw by tossing together the thinly sliced cabbage, lime juice, oil, and salt. Chill while you make the rest of the sandwich.
Combine the flour and remaining 1 tablespoon Red Tuxedo in a large bowl. Drizzle a bit of chicken brine into the flour mix to make some little crunchies! Dip the chicken breast into the flour mixture, then back in the brine and the flour again. Set aside on a cooling rack while you heat the oil.
Heat the oil for frying in a large, deep straight sided pot, such as a dutch oven. When the oil reaches 375 degrees F, add the chicken pieces two at a time and fry until golden and crisp, about 8 minutes total. The chicken should reach an internal temperature of 165 degrees F. Move to a cooling rack to drain.
Combine the Fly By Jing Sichuan Chili Crisp to a heat proof bowl and ladle in 1/2 cup of the hot fry oil (carefully, it might pop a bit!) Add the chicken pieces one at a time to coat and return to the cooling rack to drain.
Build the sandwiches by toasting the buns, smearing with a bit of mayo, adding a chicken breast, and then topping with the slaw and top bun.