Preheat the oven (if baking):
Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper or lightly grease it.
Mix the ingredients:
In a large mixing bowl, combine the ground meat, breadcrumbs, Parmesan, egg, garlic, parsley, milk, salt, pepper, oregano, and red pepper flakes. Use your hands or a spoon to gently mix until just combined. Avoid overmixing to keep the meatballs tender.
Form the meatballs:
Scoop about 1 to 1.5 tablespoons of the mixture and roll it into a ball. Repeat with the rest of the mixture, placing the meatballs on the baking sheet or a plate if pan-frying.
Cook the meatballs:
To bake: Arrange the meatballs on the prepared baking sheet and bake for 18–20 minutes, or until browned and cooked through.
To pan-fry: Heat a few tablespoons of oil in a skillet over medium heat. Cook the meatballs in batches, turning frequently, for 8–10 minutes until evenly browned and cooked through.
Serve:
Serve the meatballs with marinara sauce over pasta, in a sub roll with melted cheese, or on their own as an appetizer.