Now that you have your ingredients ready, let’s walk through the simple steps to create mouthwatering meatball subs:

1. Preheat Oven: Set your oven to 375°F (190°C) to prepare for baking the meatballs.
2. Prepare Mixture: In a large bowl, combine the ground beef, ground pork, breadcrumbs, Parmesan cheese, egg, minced garlic, oregano, salt, and pepper. Mix until just combined.
3. Form Meatballs: Roll the mixture into meatballs, about 1-1.5 inches in diameter, and place them on a baking sheet lined with parchment paper.
4. Bake Meatballs: Bake in the preheated oven for about 20-25 minutes until they are cooked through and golden brown.
5. Prepare Sauce: While the meatballs bake, heat olive oil in a saucepan over medium heat. Add the marinara sauce and dried basil. Simmer for about 5-10 minutes until warmed through.
6. Combine Meatballs and Sauce: Once the meatballs are done, carefully add them to the simmering marinara sauce. Stir to coat the meatballs generously.
7. Prepare Rolls: Cut the sub rolls lengthwise, creating a pocket for the filling.
8. Assemble Subs: Spoon a generous amount of the meatball and sauce mixture into each sub roll. Top with shredded mozzarella cheese.
9. Melt Cheese: Place the assembled subs on a baking tray and put them back in the oven for 5-10 minutes, or until the cheese is melted and bubbly.
10. Garnish and Serve: Remove from the oven, and if desired, garnish with fresh basil or parsley before serving.