01 -
Pound chicken to even thickness. Rub with olive oil, salt, pepper, paprika, and garlic powder. Grill or pan-sear over medium-high heat until cooked through (internal temperature 74°C), about 6-7 minutes per side. Let rest, then slice into strips or chunks.
02 -
In a bowl, whisk together mayonnaise, apple cider vinegar, lemon juice, horseradish, Dijon mustard, garlic powder, salt, pepper, and cayenne (if using) until smooth. Adjust seasoning to taste and chill until ready to use.
03 -
Butter the inside of each sub roll. Toast on a skillet or grill until golden and crispy.
04 -
Layer each toasted roll with a bed of lettuce. Add sliced chicken, then drizzle generously with white BBQ sauce. Top with tomato slices, pickles, or red onions if using. Serve warm with extra sauce on the side.