I reccomend browning all meatballs in oil first, but only just for browning, NOT to complete the cooking
finish the meatballs by cooking them on a sheet pan in the oven.
this way your balls will be thoroughly cooked but not too crusty on the outside.
sauce them after they are cooked, as suggested.
the size of the ball determined how hot and how long.
a 350- 400 degree oven
the bigger the ball the lower the heat and longer the cook time.
ping pongball size 400 degrees 20 minutes
350 degrees 1 hour.
egg or flour is a good binding agent to keep the balls in shape but if you are grinding ingredients with the meat, especially pork, a binder is not required. refrigerating your balls for an hour after you shape them also helps to keep their shape and may elininate the need for a 'binder' like flour eggs or breadcrumbs.
if you choose to use a binder, I reccomend crushed , flavored croutons, depending on your recipe.