1. Melt 2 Tbsp. butter in a large heavy saucepan over low heat; add chopped green chiles and minced onion, and cook 3 to 4 minutes or until softened. Whisk in 2 Tbsp. flour, and cook 1 minute. Whisk in milk and beer, and cook, whisking constantly, 3 to 4 minutes or until mixture is thickened. Add shredded cheese by 1/2 cupfuls, stirring until melted after each addition. Stir in ground cumin and salt. Serve warm with tortillas chips.