Heat 1 tablespoon of vegetable oil in a large skillet over medium heat.
Add the sliced onions and green bell peppers to the skillet and sauté for 5-7 minutes until softened and slightly caramelized. Remove from the skillet and set aside.
Add the remaining 1 tablespoon of vegetable oil to the skillet and increase heat to medium-high.
Add the ground beef to the skillet, breaking it up with a spatula. Cook for 5-7 minutes until browned and cooked through.
Add the minced garlic, Worcestershire sauce, salt, and black pepper to the beef. Stir to combine and cook for an additional 1-2 minutes.
Return the sautéed onions and bell peppers to the skillet with the beef. Stir to combine and heat through.
Preheat the oven to 350°F (175°C).
Slice the hoagie rolls lengthwise without cutting all the way through.
Divide the beef mixture evenly among the hoagie rolls.
Top each sandwich with 2 slices of provolone cheese.
Place the sandwiches on a baking sheet and bake in the preheated oven for 5 minutes or until the cheese is melted.
Remove from the oven and serve immediately.