In a large mixing bowl, combine ground beef, breadcrumbs, beaten egg, grated Parmesan, minced garlic, salt, black pepper, and milk. Mix until well combined.
Form the mixture into meatballs, about 1 inch in diameter.
Heat olive oil in a large skillet over medium heat. Add meatballs and cook until browned on all sides, about 5 minutes.
Transfer the browned meatballs to a baking sheet and bake in the preheated oven for 20-25 minutes, or until cooked through.