While macaroni is cooking, in 3-quart saucepan, melt butter over medium heat. Cook and stir onion in butter 2 to 3 minutes or until softened. Stir in flour; cook and stir 1 minute. Gradually stir in half-and-half, mustard, pepper sauce and salt; heat until thickened and bubbly, stirring constantly, about 5 minutes. Stir in beer. Remove from heat; let stand 2 to 3 minutes. Stir in cheese until melted. Add sausages to cooked macaroni. Stir in cheese sauce. Spoon macaroni mixture into casserole.