When I do mine, I use extra lean mince, mix it with egg, add onions and crushed garlic then make them into meatball shapes and place them on grease proof paper on a baking tray and then put them in the fridge for a couple hours to firm them up, then I make a sauce with passata, beef stock, mushrooms and garlic and simmer for 10 minutes, then in a seperate frying pan, brown the meatballs all around, then add the meatballs to the sauce and cook for about 20 minutes or until cooked all the way through.