What you'll need:
Meatless meatballs (I used Quorn's and highly recommend them)
Diced tomatoes or tomato sauce of your choice
Pepper and onions
Parmesan cheese, mozzarella cheese and/or provolone cheese
Heat about 2 tablespoons of olive oil in a skillet over medium heat. Once the oil is heated, add your meatballs. I used Quorn's "Meatless Meatballs"--a meat and soy free option that seriously tastes like the real thing.
Once the meatballs have been browning for a few minutes, add your peppers and onions. I used a frozen blend, but if you use fresh ones, you can add them later because they won't have to cook as long.
Cook your meatballs according to the instructions on the package. Mine had to cook for about 13 minutes. When your meatballs are cooked, slice them in half to make sure the insides are cooked.
Add your diced tomatoes. I just eyeballed this, so add as much sauce as you'd like. I also added a few shakes of Parmesan cheese.
Stir everything together and let it simmer until it thickens a bit.
Put two slices of bread on your plate. Sub rolls also work great for this.
Put down your mozzarella or provolone cheese onto your bread.
Pile on your meatballs and sauce and cover with more cheese if desired.
Close it up and enjoy!
This sandwich is easier to eat in a sub roll, but it tastes just as great with regular sliced bread. It does get messy, so I ate mine with a knife and fork.