Tip! You can use store-bought meatballs if you like. Look for Italian meatballs, either fresh or pre-cooked frozen meatballs. For fresh meatballs, cook according to the package instructions, then add to the simmering sauce. For pre-cooked frozen meatballs, add them directly to the simmering sauce from frozen and simmer with the sauce until thawed and warmed through.
For the meatballs:
Preheat oven to 450F. Add bread to a large bowl, pour milk over. Let it stand to soak. In another bowl, combine the rest of the ingredients. Gently squeeze the liquid out of the bread and add it to the meat mixture. Form into meatballs about golf ball-sized (will make about 20). Place onto a foil-lined baking sheet. Bake 20-25 minutes or until deeply golden. Make the marinara sauce while the meatballs are cooking.
Tip! You can use store-bought marinara sauce instead of making your own. Simply add to a large saucepan and heat.
For the marinara sauce:
Pour the canned tomatoes with juices into a large bowl and crush with your hands. Add 1 cup of water to the empty can and swirl it around to get any leftover tomato juices in the can. Set aside.
Heat the oil in a large, wide and shallow skillet over medium heat. When it is hot, add the garlic. As soon as garlic starts to sizzle, add the tomatoes. Do not let the garlic brown. Add about half of the reserved tomato water, the red pepper flakes, salt, and fresh basil. Stir to combine. Simmer the sauce until thickened, about 15 minutes. If the sauce is too thick, add additional water from the can as needed.
When the meatballs are cooked, add to the simmering marinara sauce.
To assemble the sub:
Make the garlic butter by combining the olive oil, melted butter and garlic in a small bowl.
Split the sub rolls lengthwise and place them onto a baking sheet. Brush the cut side of the rolls with garlic butter. Spoon meatballs with sauce onto one side of the sub roll. Top with chopped fresh basil and shredded cheese.
Place the baking sheet on a rack about 6" from the oven broiler and broil until the cheese is melted and the bread is toasty, about 4- 5 minutes. Watch closely to avoid scorching the bread.
Place the bare roll side on top of the meatball side. Cut the subs in half in the middle to form two serving pieces.