Heat olive oil in a large skillet over medium-high heat.
Add sliced peppers and onions to the skillet and cook for 8-10 minutes, stirring occasionally, until softened and caramelized.
Add shredded chicken and garlic powder to the skillet, season with salt and pepper, and cook for 3-4 minutes until chicken is heated through.
Layer provolone cheese over the chicken mixture, reduce heat to low, and cover the skillet for 1-2 minutes until cheese melts.
Divide the cheesy chicken and vegetable mixture among the toasted hoagie rolls and serve immediately.