You need some dried chiles or a decent _pure_ chile powder. If you check the ingridents and it says it has oregano in it, you don't want it.
First, take about 4 dried peppers. I used 2 anchos, 1 chile guajillo (aka New Mexico chile), and 2 smallish chile negro. Pop them in a pan and toast until they are fragrant and a lighter color. They should be leathery and pliable. Toss them in a bowl with warm water, weight with a dish, and run off for about 20 minutes.
When you return, the water should be darker and if you tear a pepper open, you should find a mushy interior layer. Remove the ribs and seeds and toss the peppers in a blender. Add about a half an onion, a half can (or more) of tomatoes, 6 cloves of garlic, a pinch of oregano, and maybe a bit of cumin. Whirl the stuff, and if it's not acting liquid, add some of the soaking water.
Strain using a strainer to get rid of the seeds / skins. You should have a red paste that acts like a thin yogurt.
Heat a non reactive pan (i.e. not cast iron) with 1 TB of fat (I used lard) and 1 TB of flour. Stir until the flour is a pale brown and turn on your exhaust fan. Pour in the pepper paste and about 1 cup of broth.
Heat on low, stirring occasionally until the sauce has thickened. Taste for salt, and it's done.
What can you do with this?
1. Stew meat in it in a crock pot / pressure cooker.
2. Enchiladas. Tortillas, cheese, tortillas, greased pan, sauce. Bake till soft and lovely.
3. Add to chilli.