Beef Zucchini Meatballs

Name: Beef-Zucchini Meatballs
Ingredients: 1 zucchini, grated; 8 ounces ground beef, preferably 90 percent lean; 1 cup cooked millet , or quinoa; 2 cloves garlic, minced; 2 tablespoons chopped flat-leaf parsley; 1 large egg, lightly beaten; Kosher salt and freshly ground pepper; Extra virgin olive-oil, for drizzling; Roasted spaghetti squash or sauteed zucchini spirals, for serving; 3 cups marinara sauce , for serving; Freshly grated Parmigiano-Reggiano and fresh basil leaves, for serving