In a large bowl, mix together the beef, bread crumbs, milk, onion, garlic, cheese, salt, peppers, egg, and fold together until everything is fully combined. Form into bite-size balls using your hands or a small cookie scoop to form the meatballs.
In a large deep pot, heat the oil of medium heat, add in half of the meatballs, and brown on all sides, about 5 to 7 minutes. Remove the cooked meatballs and repeat the process with the other half of the uncooked meatballs, add in more oil if needed.
*To make a quick pasta sauce, use the same pot and pour in a 28 ounce can of crushed tomatoes, 2 tablespoons tomato paste, 1 tablespoon of minced garlic, 1 tablespoon basil, ½ tablespoon dried oregano, ½ tablespoon dried rosemary, and salt and pepper to taste. Bring the sauce to a low boil on medium heat, then reduce heat, cover and simmer for 10 minutes to allow the flavors to come together.
Add the meatballs back into the sauce and simmer another 5 to 10 minutes until the meatballs are heated throughout. Serve with cooked spaghetti.