Sometimes, either due to dieting or health reasons, bread is simply off the table. Don't worry, you can still have a meatball sub!
Let there be meatballs! In a large bowl, combine ground beef, garlic, egg, bread crumbs and parsley. Give 'em a generous seasoning of salt and pepper, then mix it all up with a spatula until just combined.
With your hands, form the meat into 12 evenly sized balls. In a large skillet over medium-high heat, heat up the oil. Add the meatballs in a single layer in the skillet and sear on all sides until a nice crispy crust develops. Should take about 2 minutes, then you'll have to flip them over and hit 'em for another 2 minutes.
Pour marinara around the meatballs and stir until the meatballs are fully sauced. Mmm, love that smell. Simmer for 10 more minutes, then remove the skillet from the heat.
Place 2 to 3 meatballs on one slice of provolone. Don't overload it or the meatballs will fall right out. Sprinkle with Parmesan and parsley and fold over the cheese to make a sandwich. If you'd like, stick a toothpick through the top of the cheese into the middle meatball. This'll help hold the cheese in place, as well as just make it look pretty.
Repeat step 4 until all of your meatballs are sandwiched. Serve it up!