Combine ground chuck, chopped onions, egg, salt, and pepper in a bowl.

Mix well until all ingredients are incorporated.

Roll the mixture into small, even-sized meatballs.

Heat a small amount of vegetable oil in a skillet over medium heat.

Brown the meatballs in the skillet, turning frequently to ensure even cooking.

Drain the meatballs on a paper towel-lined plate to remove excess oil.

Serve immediately.