Cook elbow macaroni according to package directions for 7 minutes;drain. Set aside. In a pan, melt butter or margarine add flour slowly,stirring continually. Slowly add milk, stirring continually. Stir untilmixture is smooth, add 1 cup cheese slowly, stirring continually. Continueto stir and cook mixture until it just thickens. Add chopped onions,mustard, green peppers, stir and remove from heat. Arrange macaroni in abuttered 2.5 or 3 litre casserole. Pour mixture over macaroni. Spread theremaining cup of shredded cheese over top of macaroni mixture. Sprinklepaprika on top. Bake, uncovered, at 180ºC or 30 minutes. If you likeham, put two cups of lean cubed cooked ham in the mixture before pouringover macaroni.