I make killer meatballs. The key is to taste a few test meatballs before cooking the whole batch. Even with the same ingredients, the balance between these makes a huge difference in the final product and it's something you have to get a feel for
2 lbs ground beef (Chuck not ground round or sirloin)
1 cup grated Locatelli Romano pecorino cheese (grate this yourself)
2 eggs (3 at MOST and only if it's dry)
1.5 cups bread crumbs. I do this with fresh (not day old), bakery bread, which I cut up, dry out in an oven/toaster oven at 300F convection for 20 minutes, then cut up finer with a food processor or knife. It's ok to have pieces that are as big as 1/4 inch in size.
1 bunch of fresh parsley, chopped
6 cloves of fresh garlic, chopped pretty small, but not pressed.
1 tablespoon dried oregano, crushed by hand
Kosher or sea salt, fresh ground black pepper to taste, but don't be shy
Handle the meat lightly. Mix by pulling it apart, not pressing it or mashing it together. Remember, just like gluten, meat protein tightens when you work it, so be gentle.
Pour just enough olive oil to coat pan, maybe 1/8 inch. Mix a tiny flat 1 inch circle and fry it up on both sides and taste it. Adjust oregano, salt and pepper and repeat until you are satisfied. This is where you need a bit of experience.
Then make your meatballs and cook them. The balls should be fairly loose, not pressed super tight. Don't over crowd the pan. The heat should be high enough so that the balls sizzle, but not so high that they pop (good rule for all meats). At first they stick to the pan, but as they brown, they will release. Try not to force them and only turn when they release themselves (1 in 10 you kind of have to force). Shake the pan gently to see which ones are loose and ready for turning. Brown on all sides. Don't turn too frequently. Do one side till it's brown then turn. You may have to add a bit more oil as you go, depending on th meat. Some lean cuts soak up oil, some fattier cuts give off oil. Really you don't want very lean meatballs.
Empty 2 cans of good tomatoes (I like Cento) into a pot and grind with an emersion mixer (or food processor). Just a light blend, not a puree. Simmer, put the meatballs in sauce as they are done. You can add some romano cheese to the sauce to and at most 1 teaspoon of sugar if you need it. These will mellow out any bitterness. Better to go heavy on the romano and light on the sugar. Simmer. You can eat right then, or chill for day. When they are off the stove, push a whole bunch of unchopped parsley into the sauce. Cool a bit then move the whole pot to the fridge for a day. Next day, simply move back to the stove and simmer again. Once up to temp, throw out the parsely as it's released all it's flavor and is now bitter.
That's pretty much it. That's your sunday gravy and meatballs for your pizza.