Heat your oven to 425°F. Using a knife or fork, puncture holes all over your spaghetti squash. Put on a baking sheet and bake for 45 minutes until you can pierce the skin with a fork easily. Remove from the oven and let cool.
While the spaghetti squash is cooking, heat your fat over the stove. Add the diced onion and cook for a couple of minutes until translucent. Next, add garlic and tomatoes or tomato sauce. If using the long method, let this simmer for a while until a lot of the water has cooked out of the tomatoes, then puree or mash with a potato masher for a smoother texture. If using the short method, you can go ahead and add the rest of the ingredients.
Cook your meat in a separate pan, then add to your tomato mixture. Fill in with your herbs, tomato paste, salt, and pepper. Let simmer until you’re ready to put it on the squash. Once the squash is cooled to the point you can handle it, cut it in half, and scrape out the insides, it will fall apart in string form, creating ready-made noodles! Top with sauce and enjoy.