Mix all spices in a bowl. Spread them out on a plate.
Heat a non-stick skillet to medium-high. Place the melted butter in a bowl. Dip each chicken fillet in the butter.
Coat the chicken breasts with the spices by pressing them into the spice mixture on both sides.
Heat 2 tablespoons of canola oil in the pan. Carefully place the chicken fillets in the skillet and fry until fully cooked and blackened on both sides (about 3 to 5 minutes per side). The internal temperature should reach 165°F.
Slice the chicken into strips on a cutting board.
Add the strips to the ciabatta buns along with the mayo, lettuce and red onion.
Serve!
Video
Notes
Leftover cooked chicken can be refrigerated for up to 3 to 4 days.
You can freeze the buns to keep them fresher. Just thaw them at room temperature a couple of hours before preparing the sandwiches.