In a mixing bowl, combine the Cajun seasoning, Dijon mustard, honey, and lemon juice. Whisk until smooth and well combined.
Place the chicken breasts in a large zip-top bag or a shallow dish. Pour the marinade over the chicken, ensuring each piece is well coated. Seal the bag or cover the dish and refrigerate for at least 30 minutes, or up to 4 hours for maximum flavor.
Preheat your grill or skillet over medium-high heat. Remove the chicken from the marinade and discard any leftover marinade. Grill or cook the chicken for about 6-7 minutes per side, or until the internal temperature reaches 165°F (75°C). Place a slice of provolone cheese on top of each chicken breast during the last minute of cooking.
While the chicken is cooking, lightly butter the insides of the pretzel buns and place them cut-side down on a hot skillet or grill for 1-2 minutes, until golden brown.
Assemble your sandwich by placing a piece of chicken on the bottom half of each pretzel bun, topping with your favorite toppings, and placing the top half of the bun on.
