In a good sized pot, saute dash of olive oil, garlic, & spices over medium high heat for 1-2 minutes( just until you get the nice aroma). Add diced onion, cook until transparent.
Add tomato sauce & paste, stir until well blended. Reduce heat. Add meatballs. (You can start putting subs together now, but I like the sauce to simmer for a bit if I have time.)
For ease of cleanup, line a large baking sheet with foil. Open your rolls and sprinkle cheese to your liking.(This keeps meatballs from going through the bread.) Add meatballs & sauce. Top with more cheese.