Meatball Marinara Sub - Sensationalsandwiches

Ingredients

• 500g ground beef
• 1 large egg
• 1/4 cup breadcrumbs
• 1/4 cup grated Parmesan
• 2 minced garlic cloves
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 1 teaspoon dried oregano
• 800g tomato passata
• 1 small finely chopped onion
• a handful of chopped fresh basil
• 4 tablespoons softened unsalted butter
• 2 tablespoons chopped fresh parsley
• a pinch of salt
• slices of mozzarella cheese
• Parmesan