Prepare tomatoes by placing in simmering hot water for 15-20 seconds. Peel, core and arrange 1/2 inch slices on baking sheets. Season with oregano, thyme, garlic, salt and pepper. Drizzle with olive oil. Bake at 350 degrees for about an hour. Place roasted tomatoes in food mill and process. For thicker sauce, reduce in saucepan over medium heat for as long as desired.