01 - Preheat the oven to 400°F for toasting the rolls and melting the cheese.
02 - Heat 1 tbsp olive oil in a large skillet over medium heat. Add the sliced onion and bell peppers. Sauté for 8–10 minutes, stirring occasionally, until softened and lightly caramelized. Remove from skillet and set aside.
03 - Add another 1 tbsp olive oil to the skillet. Add the sliced chicken, salt, pepper, garlic powder, and paprika. Cook for 6–8 minutes, stirring occasionally, until the chicken is cooked through and lightly browned.
04 - Return the sautéed vegetables to the skillet with the chicken. Stir to combine and heat through for 2 minutes.
05 - Slice the hoagie rolls lengthwise, leaving one edge intact. Lightly butter the insides of each roll. Place on a baking sheet cut side up and toast in the oven for 3–4 minutes until just golden.
06 - Divide the chicken and vegetable mixture evenly among the toasted rolls. Top each with 2 slices of provolone cheese.
07 - Return the sandwiches to the oven for 3–4 minutes, or until the cheese is melted and bubbly. Serve immediately while hot.