In a large bowl, combine ground beef, Italian sausage, breadcrumbs, eggs, Parmesan, garlic, Italian seasoning, salt, and pepper. Mix until evenly combined, but don’t overwork it.

Form the mixture into evenly sized meatballs, about 1 ½ inches in diameter.

Air Fryer Method: Preheat the air fryer to 375°F (190°C). Place meatballs in the basket, leaving space between them. Cook 10–12 minutes, shaking halfway through.

Stovetop Method: Heat olive oil in a skillet over medium heat. Brown meatballs on all sides, then remove.

Transfer meatballs to a pot with marinara sauce. Simmer over low heat for 10–15 minutes until cooked through and flavorful.

Slice the hoagie rolls open. Toast lightly if desired.

Place 3–4 meatballs per roll, spoon extra marinara over them, and top with provolone or mozzarella cheese.

Pop assembled subs under the broiler or in the air fryer for 2–3 minutes until the cheese is melted and bubbly.

Enjoy immediately while hot and gooey! Perfect with chips or a side salad.