In a medium bowl, combine the chicken, jalapeño brine, salt and pepper. Cover with plastic wrap and chill in fridge for at least 4 hours or overnight. Just keep in mind that the brine will begin to cook the chicken and it might make it white, but that's okay.
In a shallow dish, whisk together the flour, cornstarch, salt, pepper, garlic powder, onion powder, paprika and cayenne pepper. In a separate shallow dish, whisk together the egg, buttermilk, and hot sauce.
Drain and discard the chicken marinade. Coat each chicken thigh in flour, patting it on both sides to coat evenly. Transfer to a wire rack set over a baking sheet. Then take about 3 tablespoons of the buttermilk mixture and drizzle it into the remaining flour mixture. Give it a toss to create a crumbly texture. This will make a crunchy coating for the chicken when you go to fry it. Dip each piece of chicken into the egg and then into the flour mixture, returning to the wire rack. Once all the chicken has been coated, allow to rest in the fridge for about 30 minutes. This will ensure the coating sticks.
Fill a cast iron skillet, just about halfway up with vegetable oil and bring to 360 degrees F, using a deep-fry thermometer. Once hot, fry the chicken in batches until golden brown and crispy, flipping over half way, about 7 to 8 minutes. Drain well and transfer to a clean wire rack set over a baking sheet.
To make the sauce, in a small bowl, stir together the mayo, lemon juice, chives, garlic, salt and pepper until evenly combined.
Split the rolls in half and toast on a butter skillet or griddle on the stove. Spread each half liberally with the garlic mayo and lay a few slices of pickles onto each bottom. Place a piece of fried chicken on, and shredded lettuce. Replace with the top bun and serve. Enjoy!