Merlot, I NEVER buy frozen meatballs. I make my own. I happen to have cookie scoops (dashers is the proper name for them), that I use. After I have mixed all the meat, I then use my dasher. Take a scoop, plop it on the cookie rack, and then when that is full, I go back and roll each scoop by hand. Put in the over and bake. Turn them all once and let finish baking. When both sides are nice and brown, and crispy, I then take them out and allow to cool. Put in a zippy bag and into the freezer. Sure beats standing at the stove and turning each one and getting the stove all greasy. I put the catch pan in the fridge also. The fat solidifies and is easier to remove. Then it easier to clean.
This method allows me to rid my food of a lot of the fat. It allows me to purchase the 80% meat if I am not grinding my own. I know the fat provides a lot of the flavor in the meat. But I would rather depend on my seasonings to do that. If you use the right seasonings, you won't miss the fat.
Right now I have a bag full of meatballs that I made a couple of weeks ago. I have a large jar of pasta sauce in the fridge. I pour it into a pan, add a couple of meatballs, and I have supper in a flash. By the time the meatballs are thawed and heated through, the pasta is ready to eat.
If I have no jarred tomato sauce on hand, then a can of tomatoes with my own seasonings cooked for a short time. The meatballs with also add their flavor to the sauce.
Growing up, all the Nonas that I knew, were in the kitchen cooking for their Italian families and cooked their Sunday gravy all day. But I have since learned that even with a can of crushed tomatoes, the flavor is much fresher when it is cooked for a shorter time. I have even made a gravy with fresh tomatoes right from the garden. Crush them and cook like you would a can of crushed tomatoes.