The secret is:
2 cans tomato sauce (El Pato if you can get it). I then chopped up 1/2 a purple onion, 4 cloves garlic,
a small bunch of cilantro and 3 jalapeños in the blender.
Serranos if you want it spicy.
Add some chile de arbol if you want it nuclear.
I blend the onion, jalapeno, cilantro and garlic separate from the sauce and then mix it in. I add salt to taste. I make this every week for tacos, burritos, omelettes, quesadillas and just to snack with chips