Ranchero Sauce 2 tablespoons cooking oil 1/4 cup of chopped onion 2 cloves of garlic, chopped 1 serrano or jalapeno chile, sliced 3 cups diced tomatoes. 1 teaspoon oregano 1 teaspoon cumino 1 1/2 teaspoon ground chile (Chilie Powder) Salt to taste Start by heating the oil, and saute the garlic, serrano and onions for 2-3 minutes. Reduce the heat and add in the tomatoes. Cook the tomatoes for about 5 or 6 minutes until they become wilted. Roma's may need more cooking time as they are not as juicy. Add in the seasonings and simmer for about 5 more minutes. You can serve the sauce as is, or you can let the sauce cool and blend it.