-
Preheat broiler on high. Make sure oven rack is about 4 inches below the heat source. Rub 1 teaspoon olive oil over the surface of a rimmed baking sheet.
-
In a large sauce pot, heat the remaining 5 teaspoons olive oil over medium heat. Add two cloves of garlic and cook until golden, about 3 minutes. Add tomatoes, 1/2 teaspoons salt, sugar, and 1/2 teaspoon red pepper flakes (if desired). Bring to a boil, reduce heat, and simmer, covered, for 10 minutes.
-
Meanwhile, in a food processor, combine zucchini, carrot, onion, remaining garlic, and parsley. Pulse until finely chopped. Transfer vegetable mixture to a large bowl. Add the beef, oats, parmesan, remaining salt, remaining red pepper flakes (if desired), and egg. Mix well.
-
Shape mixture into meatballs 1 1/2 inches in diameter. Arrange evenly on the prepared baking sheet. Broil until the tops of the meatballs are browned, about 5 minutes.
-
Gently transfer meatballs to the sauce pot and continue to cook, covered, for 10 minutes or until meatballs are cooked through. Remove from heat.
-
Serve as an appetizer or over cooked spaghetti as a main course. Garnish with additional parsley and parmesan if desired.