01 - Place chicken pieces in a non-reactive bowl and submerge in pickle brine and hot sauce. Cover tightly with plastic wrap and refrigerate for a minimum of 2 hours, or overnight for deeper flavor penetration.
02 - In a large mixing bowl, whisk together the all-purpose flour, cornstarch, garlic powder, onion powder, smoked paprika, kosher salt, and black pepper until evenly combined.
03 - Remove chicken from the brine and discard the used marinade. Pat each piece thoroughly dry with paper towels. Dredge each chicken piece in the seasoned flour mixture, pressing firmly to ensure a complete, even coating on all surfaces.
04 - Heat vegetable oil in a deep skillet or heavy-bottomed pot to 350°F. Carefully lower breaded chicken pieces into the hot oil in small batches to avoid overcrowding. Fry for 4 to 6 minutes per side until deeply golden brown and the internal temperature reaches 165°F. Transfer to a paper towel-lined plate to drain.
05 - In a small bowl, stir together the mayonnaise and Dijon mustard until smooth. Spread the mixture generously on both halves of each slider bun. Layer the bottom bun with a lettuce half, a piece of fried chicken, and a dill pickle slice. Cap with the top bun.
06 - Serve the sliders immediately while the chicken is still hot and the coating is at peak crispness.