Roasted New Mexican green chiles makes a great sauce for enchiladas or burritos.
Heat oil in a medium saucepan over medium heat. Add onion and garlic and cook, stirring, until very soft, about 4 minutes. Sprinkle flour over the mixture and cook, stirring, for 1 minute more. Add chiles and broth; bring to a boil. Reduce heat to a low simmer and cook until thickened but still easily spoonable, 15 to 20 minutes.
Make Ahead Tip: Refrigerate for up to 3 days.