I used to make this a lot when I first had chickens and for no reason it's fallen out of favor.
1-2-3 and it's done. The tomato sauce is 14 ounces or so (about half of a large can) of whole peeled tomatoes. Obviously at the end of summer I'd be using good tomatoes from the garden or farmers market. Add the tomatoes and some of the liquid to a blender jar and then add 2 serrano chiles, one half a white onion, a very small bunch of cilantro and salt. Blend well and then "fry" the sauce in a saucepan with a spoonful of olive oil. Cook for about 10 minutes. You may need to add a little water. It's delicious and you can use leftover sauce for chile relleno or entomatados, which are like enchiladas but they use tomatoes instead of chiles as the base of the sauce.