How to Make It
Preheat the oven to 400° and grease a large baking dish with olive oil. In a large bowl, using your hands, gently mix all of the remaining ingredients except the marinara sauce. Form the ground-beef mixture into twelve 2 1/2-inch meatballs.
Arrange the meatballs in the baking dish and roast for 20 to 25 minutes, until just cooked through. Spoon the marinara sauce on top and bake until the sauce is hot, about 5 minutes. Garnish with grated cheese and chopped parsley and serve.