Prepare Meatballs: In a bowl, gently combine the ground chicken, minced garlic, torn bread, egg, salt, black pepper, garlic powder, and crushed red pepper flakes. Form the mixture into meatballs or patties.
Sear Meatballs: Heat the butter and olive oil in a skillet over medium-high heat. Sear the meatballs until they are golden brown on all sides.
Bake Meatballs: Transfer the seared meatballs to a baking dish and bake in a preheated 350°F oven for 20 minutes.
Assemble Subs: Slice the hoagie rolls lengthwise. Place a slice of provolone cheese on the bottom half of each roll. Top with the cooked meatballs, marinara sauce, and mozzarella cheese.
Finish Subs: Bake the assembled subs until the cheese is melted and golden brown, and the rolls are crispy. Garnish with freshly torn basil before serving.
