In saucepan, brown ham in butter until slightly browned. Add green pepper and onion and cook until translucent, about 5 minutes. Add flour and mix thoroughly; cook two minutes. Remove from heat and gradually stir in two cups of the milk. Return to heat and cook, stirring, until thickened and smooth. Remove from heat and add cooked macaroni shells, cubed cheese, tomato, mustard, salt and pepper. Mix well and turn into greased 2-quart baking dish. Bake at 350 F degrees for about 20 minutes. Remove from oven and check moisture content. If dish is too dry, add remaining half cup of milk. Sprinkle with grated cheese and return to oven for 10 minutes longer or until mixture bubbles and cheese begins to brown. Makes 6 to 8 servings. From old newspaper clipping. Typed for you by Joan MacDiarmid. Posted to MM-Recipes Digest V4 #4 by Kyle & Elisabetta on Feb 01, 99