In 2 quart saucepan heat margarine until bubbly and hot. Add flour, cook over low heat, stirring constantly (3 minutes). Remove pan from heat using small wire whisk gradually stir in milk. Stir until mixture is smooth. Add seasonings and cook over medium heat, stirring constantly until thickened. Reduce heat to low and cook for 10 minutes longer, stirring occasionally. Add cheese and cook, stirring constantly until cheese is melted. Add vegetables and macaroni; cook, stirring gently until vegetables are thoroughly coated and heated.