Enchilada Sauce Verde

Tomatillos are very common in Mexican cuisine and cook down nicely to a saucy consistency as do tomatoes.  You can make a green sauce using only tomatillos, or mix with tomatoes for a bit richer flavor as in this recipe. This is a great sauce for enchiladas or burrito casseroles.
1 lb ripe tomatoes, cored and coarsely diced
1 lb ripe tomatillos, peeled and quartered
1 small onion, finely diced
1/2 jalapeño pepper, minced
2 cloves garlic, minced
1/2 tsp cumin powder

In a medium saucepan, fry the onion for about 5-8 minutes to soften and begin to caramelize.  Add the garlic and jalapeño and cook another 2-3 minutes.  Turn the heat to high and add the tomatoes, tomatillos and cumin, and cook down, until they break apart.  Lower the heat to a simmer and stir often to keep bottom from burning, and to break up the veggies into the sauce.  After about 15-20 minutes, you should have a fairly smooth sauce.  If necessary, add a bit of water or broth to make a pourable sauce.  Salt and pepper to taste.