There are numerous variations of meatballs. Where I come from, a meatball is ground pork (can also be a mix of ground pork/veal) that is breaded in breadcrumbs.
Take the meat out of the fridge about 30 minutes before it is to be cooked and divide it into 4 equal parts. Shape them into relatively flat patties and season them with salt and pepper.
Let the meat sit covered until they are to be fried.
Heat a pan over medium-high heat and melt the butter in it. When the butter sizzles, the meatballs are ready to be added.
Distribute the flour, a beaten egg, and the breadcrumbs on 3 plates and coat your meatballs in them starting with the flour, then the egg, and finally the breadcrumbs.
Fry them for 5 minutes on each side and serve immediately.
Optionally, use the frying fat to pour over your meatballs or for the gravy.