Preheat oven to 400°F. Line a baking sheet with parchment paper. Set aside.
In a bowl, combine the ground beef, onion, parsley, salt, breadcrumbs, Parmesan cheese, seasonings, and egg.
1 pound 85% lean ground beef, ½ onion, ¼ cup chopped fresh Italian parsley, 1 teaspoon kosher salt, ½ cup breadcrumbs, ⅓ cup freshly grated Parmesan cheese, ½ teaspoon onion powder, ½ teaspoon garlic powder, 1 teaspoon Italian seasoning, 1 large egg
Roll the mixture into 16 balls. Place on the prepared baking sheet.
Bake for 12-15 minutes until the edges are crispy and the meatballs are 160°F internally.
While the meatballs are cooking, heat the marinara sauce in a large saucepan over low-medium heat.
16 ounces marinara sauce
When the meatballs are done, add them to the saucepan and coat them in the sauce.
Spoon four meatballs and sauce into each roll and top with shredded mozzarella.
4 hoagie rolls, 2 cups freshly shredded mozzarella cheese
Place the subs under the broiler for a couple minutes.
Finish with a sprinkle of chopped basil and/or parsley.
Chopped fresh basil