Prepare the Chicken
Slice each chicken breast in half lengthwise to create thin, even fillets. Pat dry with paper towels.
In a small bowl, mix together smoked paprika, garlic powder, onion powder, cayenne, thyme, oregano, salt, and black pepper.
Rub the seasoning blend generously onto both sides of the chicken fillets.
Cook the Chicken
Heat olive oil in a large skillet or grill pan over medium-high heat.
Add the chicken fillets and cook for 3–4 minutes per side, or until the internal temperature reaches 165°F (74°C) and the chicken is blackened and slightly charred. Remove from heat and let rest for a few minutes.
Make the Alabama White Sauce
In a mixing bowl, whisk together mayonnaise, apple cider vinegar, Dijon mustard, horseradish, garlic powder, onion powder, black pepper, sugar, and lemon juice until smooth. Adjust seasonings to taste.
Assemble the Sliders
Toast the slider buns lightly, if desired.
Spread a generous layer of Alabama white sauce on the bottom half of each bun.
Place a piece of blackened chicken on each bun, then top with lettuce and pickle slices, if using. Add more sauce to the top bun, then assemble the slider.