For the Nashville hot sauce: Combine chicken stock, brown sugar, cayenne, Carolina reaper powder, if using, chili powder, paprika, salt, Scotch bonnets, anchos, guajillos and scorpion chiles, if using, in a saucepan. Boil and reduce by half, then let cool. Puree in blender, then add mustard and combine. Slowly add melted fat.
For the brine: Mix 1 gallon water with 1 cup salt in a large container. Submerge the chicken pieces in the brine and let sit overnight, refrigerated.
Drain the chicken and cover in buttermilk, then let sit overnight.
For the fried chicken: Combine the flour, masa, cornstarch, celery salt, coriander, seafood seasoning, salt and pepper in a big bowl. Toss in chicken parts and coat well, then let rest, refrigerated, for 30 minutes.
Bring oil to 300 degrees F in a deep-fryer.
Fry chicken in batches until it reaches internal temperture of 160 degrees F, about 20 minutes. Toss in bowl with Nashville Hot Sauce.
For the biscuits: Meanwhile, grate butter with a cheese grater, then freeze again.
Mix together flour, baking powder, salt, sugar, baking soda and shortening in a bowl, then freeze, 3 hours.
Mix frozen butter, dry mixture and buttermilk together in a large bowl until dough comes together, then lay out on a floured surface and roll out to about 2 inches thick. Fold into thirds, then repeat the rolling and folding 3 more times. Cut into 20 biscuits and place on a baking sheet lined with parchment paper. Freeze for 3 hours or up to overnight.
Preheat the oven to 350 degrees F. Take biscuits out of freezer and sprinkle with salt. Bake for about 15 minutes.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.