Preparation / Directions:
In a medium heavy-bottomed saucepan, melt the butter over medium-low heat. Whisk in the flour and let bubble without browning for about 2 minutes
Whisk in the half and half and beer. Bring to a simmer over medium heat. Reduce the heat to low and cook until thickened, about 5 minutes.
Meanwhile, in a medium skillet, heat the oil over medium heat. Add the onion, chili pepper and garlic and cook, stirring often, until the onion is softened, about 3 minutes. Add the tomatoes and cumin and cook until the excess moisture is evaporated, about 3 minutes. Stir the vegetables into the sauce. (This sauce base can be prepared up to 1 day ahead, cooled, covered and refrigerated. Reheat over low heat.)
Gradually stir the cheese into the sauce. Cook until the cheeses are melted, but do not boil. Season with salt and hot sauce to taste. Transfer to a serving bowl (a small electric slow cooker or a thick ceramic soup bowl works best to hold the heat> and serve warm, with the tortilla chips for dipping.