•Feel free to omit the garlic and/or onion if you are not a fan. If you enjoy the onion flavor but not the pieces, allow half an onion (not chopped) to simmer along with the sauce, and then remove prior to serving.
•You may omit the pepperoni, but this small amount adds something extra special to this sauce. For a meat lovers version, you can also sauté some sliced, fully cooked sausage before adding the sauce to the pot. If you go heavy on the meat, you may wish to have extra tomato sauce or puree on hand (basic canned is fine at this point) to achieve the best ratio of meat to sauce. I find that one pound of meat is a good amount for every 4 cups of sauce, but you can absolutely adjust to preference with more or less sauce. After the first jar of quality marinara, I tend to wing it sometimes and even used a 16-ounce jar of pizza sauce I had on hand recently. This sauce is the perfect vehicle for raiding your pantry and freezer for tomato and meat ingredients.
•Sliced or diced mushrooms could be added with the onions.