Preheat the oven: Begin by preheating your oven to 350°F (175°C).
Spread the mayo: Take the bottom half of the ciabatta and spread 1/4 cup of mayo evenly across it.
Add Dijon mustard: On the top half of the ciabatta, spread 1/4 cup of Dijon mustard.
Layer the provolone: Place 4 slices of provolone cheese on the mayo-covered bottom half of the ciabatta.
Add the meats: Layer 8 oz of deli-sliced turkey breast followed by 8 oz of deli-sliced chicken on top of the provolone.
Crisp up the bacon: Lay down 8 slices of cooked turkey bacon on top of the meats for extra crunch and flavor.
Add vegetables: Top the sandwich with sliced tomato, shredded lettuce, and thinly sliced red onion. Sprinkle with salt and pepper according to your taste.
Cover with the top ciabatta half: Gently place the top half of the ciabatta over the fillings.
Wrap and bake: Wrap the entire sandwich in foil and place it in the oven. Bake for 10-15 minutes, or until the cheese is melted and the sandwich is heated through.