Prepare the Meatballs: In a large bowl, combine the ground meat, breadcrumbs, grated onion, minced garlic, egg, chopped parsley, salt, pepper, and dried oregano. Mix well until all ingredients are evenly combined. Form the mixture into small meatballs, about 1 inch in diameter.

Brown the Meatballs: Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the meatballs and cook, turning occasionally, until they are browned on all sides, about 5-7 minutes. They do not need to be fully cooked at this stage as they will finish cooking with the vegetables. Remove the meatballs from the skillet and set aside.

Cook the Vegetables: In the same skillet, add an additional tablespoon of olive oil. Add the chopped onion and cook until translucent, about 3 minutes. Stir in the minced garlic, bell pepper, zucchini, carrot, and mushrooms. Cook for 5-7 minutes, stirring occasionally, until the vegetables start to soften.

Combine Meatballs and Vegetables: Add the diced tomatoes, dried basil, dried thyme, salt, and pepper to the skillet with the vegetables. Stir to combine, then return the meatballs to the skillet, nestling them among the vegetables. Cover and simmer on low heat for 15-20 minutes, or until the meatballs are cooked through and the vegetables are tender.

Serve: Serve the meatballs and vegetables hot, garnished with additional fresh parsley if desired. They pair well with rice, pasta, or a crusty loaf of bread.