Step 1: Roast the garlic cloves by preheating the oven to 250°F. Place the cloves into a stoneware baking dish and drizzle to 2 tablespoon of olive oil, stirring to coat evenly. Cover tightly with aluminum foil and roast for an hour and a half, checking half-way through with a quick stir. Garlic is done when it mushes easily with a fork.
Step 2: While the garlic is roasting, begin simmering the sauce. In a large pot or Dutch oven, combine the two cans of tomatoes, juice and all, the can of tomatoes with green chilies (drained), the tablespoon of crushed red pepper, and one tablespoon each of Oregano and Basil. Bring to a boil, then reduce to simmer, uncovered.
Step 3: Once the garlic has finished roasting, remove and increase oven temp to 425°F. Spoon half of the roasted garlic into the sauce, using a hand blender to emulsify the sauce a bit, but do leave some chunks of tomato.
Step 4: Prepare the peppers and onions for roasting by cutting the peppers in half lengthwise, removing the inner seeds and membrane. Quarter the onions and separate the layers. Toss the peppers and onions together in a large bowl, along with the remaining roasted garlic and some olive oil. Transfer to shallow metal pan lined with foil (easy clean up), spread into a single layer and sprinkle with salt and pepper. Roast for 25 minutes, then turn them over and continue roasting for 20-25 minutes longer until nicely browned on the edges. When finished, transfer to cutting board and let them cool.
Step 5: If using ground beef, brown ground beef in skillet, adding a tablespoon each of oregano and basil, and a few dashes of salt & pepper. Add cooked ground beef to sauce and mix thoroughly.
Step 6: Once the roasted peppers and onions have cooled, rough-chop them and add them to the sauce. Continue to simmer as you boil your pasta, prepare salad and bake your garlic bread.
Step 7: Top your spaghetti with sauce and freshly grated mozzarella cheese instead of parmesan.