Harvest-Time Meatballs

In a bowl, mix together ground beef, egg, chopped onion, dry bread crumbs, milk, salt, pepper, and Worcestershire sauce. Shape the mixture into 1 1/2-inch balls. Heat oil in a large skillet and cook the meatballs over medium heat until brown; about 20 minutes. Drain. Melt butter in a large skillet. Add crushed garlic clove, thyme, sliced mushrooms, and sliced zucchini; cook over medium-high heat for about 5 minutes, stirring occasionally. Add the cooked meatballs; cover, and simmer, stirring occasionally, until the vegetables are tender, about 10 minutes. Sprinkle with salt and grated Parmesan cheese. Add sliced tomatoes, cover, and heat for 2 to 3 minutes.