Heat olive oil in a large skillet over medium heat.
Add sliced onions and bell peppers to the skillet.
Cook until they become soft, about 8-10 minutes.
Add the sliced chicken breast to the skillet.
Season with salt and pepper to taste, then continue cooking.
Stir occasionally until the chicken is cooked through, about 10 minutes.
Layer the provolone cheese over the cooked chicken and veggies in the skillet.
Cover the skillet with a lid to melt the cheese, letting it cook for about 2 minutes.
Toast the hoagie rolls on a separate pan or in the oven until golden brown.
Assemble the sandwiches by spooning the chicken, cheese, and veggies mixture into each hoagie roll.