Ranchera Sauce

Heat a griddle over medium heat or preheat a boiler on low with the broiler rack 8 inches from the broiler. Place tomatoes on griddle and cook, turning as necessary, until evenly softened and skins are blackened, 15 to 20 minutes. If using a broiler, place tomatoes on a broiler pan and broil, turning as necessary, until evenly softened and skins are blackened, about 20 minutes. Transfer tomatoes to a bowl and let cool. Peel and core tomatoes.

Working in batches of necessary, combine roasted tomatoes, chiles, and garlic in a blender and blend until smooth. Place cinnamon stick on a 6-inch square of cheesecloth and tie with kitchen twine to enclose.

Heat vegetable oil in a medium saucepan over medium heat. Add onion and cook, stirring, until onion is translucent, about 4 minutes. Add the pureed tomato mixture and bring to a boil. Stir in salt, sugar, and cinnamon. Reduce heat to a simmer. Cook until lightly thickened, about 30 minutes. If sauce becomes too thick, reduce heat and add water 1 tablespoon at a time.

Remove sauce from heat and adjust seasonings, if desired. Sauce can be made up to 3 days in advance. Let cool, cover, and refrigerate. Reheat over low heat, adding water 1 tablespoon at a time, if necessary, to return sauce to desired consistency.