As usual, my experience comes from referencing the Moosewood Cookbook.
Here we go -
Chop one cup of onion and two cloves (or more) of garlic.
Prepare three cups of chopped, peeled tomatoes. Blanch the tomatoes to get the skins to peel off, then chop them up.
Have ready 1 cup of water, 1 tsp. salt, 1 tsp. cumin, 1/4 tsp. ground coriander, 2 tsp. dry red wine, 1/2 tsp cayanne, 1/4 tsp black pepper, 1/2 tsp chili powder, 2 Tablespoons tomato paste, and two Tablespoons olive oil.
Sauté onions and garlic in olive oil with 1/2 tsp salt until the onions are clear. Add spices. Transfer to your heavy pan and add the peeled tomatoes, water, tomato paste and wine. Add remaining salt. Cover and simmer 1/2 hour -- longer is better.
Hot spices tend to get hotter as they cook - so pay attention. You might want to add some minced jalapenios (minus the seeds) - just to scare the horses.
This is a very versatile sauce. Take it where you will.