01 - Place chicken pieces in a bowl and pour pickle brine and hot sauce over them. Cover tightly and refrigerate for at least 2 hours, or overnight for deeper flavor penetration.
02 - In a large 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 brine. Pat each piece dry thoroughly with paper towels. Coat each chicken piece completely in the seasoned flour mixture, pressing firmly to adhere the breading.
04 - Heat vegetable oil in a deep skillet or heavy-bottomed pot to 350°F. Carefully lower chicken pieces into the hot oil in batches, avoiding overcrowding. Fry for 4 to 6 minutes per side until golden brown and cooked through to an internal temperature of 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 and well blended.
06 - Spread the mayonnaise-mustard mixture on both halves of each slider bun. Layer a lettuce leaf half, a fried chicken piece, and a dill pickle slice on each bottom bun. Cap with the top bun and serve immediately while hot and crispy.