Easy enough, add the ingredients to a bowl, mix well and set asside
Make the cheese sauce
In a saucepan, melt the butter. Stir in the flour and cook over moderate heat for 30 seconds. Whisk in the milk and cook, whisking until thickened, about 5 minutes. Stir in the Pepper Jack cheese until melted.Season with salt, pepper and hot sauce.Let cool until spreadable.
Make the Burger
Light a grill or grill pan. Mix in the southwest seasoning,form the beef into 4 patties and brush with oil, season with salt and pepper. Grill over moderately high heat until browned outside and medium within, about 4 minutes per side. Place the burgers on the buns, top with the cheese sauce, salsa, jalapeƱos, sliced lettuce and tomato.