Preheat oven to 400°F.
Place a medium-size sauce pot over medium-high heat, add EVOO. Add the onion, carrot and celery, and cook for about 3-4 minutes. Add the thyme and cook for another minute. Add the crushed tomatoes, turn heat down to low and cook for 10-15 minutes.
In a medium-size mixing bowl, combine meats with egg, garlic, bread crumbs, milk, grated cheese, parsley, red pepper flakes and season with salt and pepper. Form into mini meatballs.
Add the meatballs to the sauce and cook for 15-20 minutes or until cooked through. Thin the sauce with chicken stock as the sauce thickens, or as needed.