OPTION 1
https://foodnetwork.co.uk/recipes/meatball-subs/?utm_source=foodnetwork.com&utm_medium=domestic
2 tablespoons extra-virgin olive oil, (2 turns around the pan)
4 cloves garlic, crushed and chopped
1/2 teaspoon crushed red pepper flakes
A handful flat-leaf parsley leaves, chopped, about 2 tablespoons
1/2 teaspoon dried oregano
1 (28 ounces) can crushed tomatoes
1 (14 ounces) can chunky style crushed tomatoes
Salt and freshly ground black pepper
4 semolina crusty sub rolls, with or without sesame seeds
1 (10-ounce) bag (2 1/2 cups) shredded provolone or Italian 4-cheese blend
Shredded basil (sweet) or shredded arugula (spicy) leaves, for garnish
OPTION 2
https://www.allrecipes.com/recipe/90321/meatball-sandwich/
OPTION 3
https://thebigmansworld.com/copycat-subway-meatball-marinara-sandwich/
OPTION 4
https://tastesbetterfromscratch.com/italian-meatball-subs/