Preheat your grill or stovetop grill pan over medium heat.
Season the chicken breasts with Italian seasoning, garlic powder, salt, and pepper on both sides.
Drizzle olive oil over the chicken and rub it in to coat evenly.
Grill the chicken for about 6-7 minutes on each side, or until the internal temperature reaches 165°F. Remove from heat and let it rest for 5 minutes.
While the chicken is resting, warm the marinara sauce in a small saucepan over low heat.
Slice the grilled chicken breasts and place them in the hoagie rolls.
Spoon marinara sauce over the chicken and top each sandwich with a slice of provolone cheese.
Place the sandwiches under a broiler for 2-3 minutes, or until the cheese is melted and bubbly.
Remove from the oven, garnish with fresh basil leaves and sprinkle with grated Parmesan cheese before serving.