In a medium sauce pot over medium to medium-high heat, melt butter. Add flour and whisk together. When pale golden, whisk in milk, then whisk in beer, bring to a bubble and let cook out a few minutes or until slightly thickened. Add mustard, spices and Worcestershire to sauce, then stir in cheese with a spoon off heat. Reduce heat to low and keep sauce warm.
Place chips on a platter or in individual serving bowls. Top with cheese sauce, chopped Italian Beef and giardiniera.