SALSA DE TOMATE VERDE COLIDA (Mexican cooked green tomato sauce, about 2 cups)
2 cups tomates verdes, drained (see note below)
1 clove garlic, peeled and roughly chopped
¼ medium onion, roughly chopped
2 or 3 chiles serranos, toasted
¼ teaspoon granulated sugar
¼ teaspoon salt, or to taste
3 tablespoons safflower oil
1. Toast the chiles by placing them on a warm comal or griddle and turning them from time to time until the skin is charred and the flesh is soft.
2. Process the ingredients in a blender until they are smooth.
3. Heat the oil in a small frying pan and cook the sauce for about 5 minutes, until it has thickened a little and is well seasoned. This sauce is used for huevos rancheros, budin azteca, and is also good mixed with shredded meat on tacos.
NOTE: If fresh tomates verdes are available, remove their papery husks, rinse them and barely cover them with water. Bring them to a boil, lower the flame and simmer them for about 10 minutes. By this time they should be soft. If you cook them over a high flame they will burst – if this happens, just drain off some of the liquid and grind the debris with the remaining water. If they remain whole, as they should, drain them and grind them with their skins and seeds, and a little of the cooking water, to a smooth sauce. They can be used immediately or stored in one or two cup containers in the freezer for future use.
from Diana Kennedy,The Cuisines of Mexico