Preheat oven to 400°F (200°C). In a large mixing bowl, combine ground meat, breadcrumbs, egg, onion, garlic, Italian seasoning, salt, and pepper. Mix until just combined (do not overmix).

Roll into 1 to 1.5 inch meatballs and place on a parchment-lined baking sheet.

Bake for 18 to 20 minutes, or until browned and cooked through. Alternatively, pan-fry in a skillet over medium heat, turning to brown all sides.

In a large saucepan, bring marinara sauce to a simmer. Add cooked meatballs and simmer for 10 to 15 minutes to let flavors meld.

Split rolls open without cutting all the way through. Optional: Brush with butter and toast in the oven for 3 to 5 minutes until lightly crisp.

Spoon meatballs and sauce into each roll. Top with mozzarella and provolone cheese.

Place under the broiler for 2 to 3 minutes, until cheese is melted and bubbly. Sprinkle with parmesan and fresh herbs if desired.

Serve immediately with your favorite sides.