Heat oil of your choice in a large skillet over medium heat. Add sliced NoBull Burgers to the skillet and cook for 5-7 minutes, stirring occasionally, until they start to brown.
Add sliced bell pepper and onion to the skillet and cook for an additional 5-7 minutes, until the vegetables start to soften.
Season the mixture with salt and pepper to taste.
Preheat your oven to 350°F.
Slice the hoagie rolls in half and place them on a baking sheet. Toast the rolls in the preheated oven for 5-7 minutes, until lightly crispy.
Divide the NoBull Burger/pepper mixture among the toasted rolls. Top each sandwich with 1-2 slices of cheese.
Return the sandwiches to the oven and bake for an additional 3-4 minutes, until the cheese is melted and bubbly.
Serve hot and enjoy!