Take 6 tomatoes or 7 tomatillos. Broil or fry in a pan until they have blackened spots (8 minutes, approximately.) If you're not sure of the quality of your tomatoes, I'd advise heavily that you wash them first, and you prune off any unpleasant spots post roasting. Plop these in a blender with 2 cloves of garlic minced or squeezed through a press.
Take 6 chile de arbol (those thin very hot dry peppers) or 1 regular dried pepper or about a tablespoon of a chili powder of your choice. Destem the peppers and fry until fragrant. Pop them in the blender.
Blend until smooth and taste. If it tastes flat, add some more tomato, lime, salt, or oregano.
End result using the chile de arbol, added tomato liquid from a can of tomatoes, and oregano is a hot salsa with some surprising depths of flavor. Next time, I'd use less chile de arbol, and more - mm - perhaps dried ancho chiles.
Edit: Re-did it with one ancho, one chile de arbol, 4 bitty garlic cloves, and a half can of diced tomatoes. Added a pinch of salt and a half tsp of oregano. Result? Closer to Salsa Ranchera - dark, rich, meaty. It lacked the killer heat and instead had a subtle burn. I missed the tomatillo bitterness though.