Line four 8x8x2-inch baking pans with heat-resistant freezer wrap. Allow= enough extra wrap to fold over top. Use one pan for each six servings or= one-fourth of the recipe. Do not line pans for food to be served without= freezing.
Add beans to boiling water; return to boiling. Boil beans 2 minutes;then= soak beans 1 hour (or overnight, if preferred).
Add salt to beans. Cook beans slowly until tender, about 1 1/2 hours. = Drain; save cooking liquid. Cook onion and green pepper in fat about 5= minutes, stirring occasionally. Stir in flour and mustard. =20 Add enough milk to the reserved bean liquid to make 1 1/2 quarts. Add the= bean liquid and milk slowly to the vegetable mixture. Cook until= thickened, stirring constantly. Stir in beans, cheese, and ham. Pour= one-fourth of mixture into each baking pan. Pack food tightly to avoid air= pockets.
TO SERVE WITHOUT FREEZING: Preheat oven to 375=B0 F. (moderate). Mix 1/4= cup fine breadcrumbs with 1 tablespoon melted butter or margarine for each= pan which will not be frozen. Sprinkle topping over bean mixture in baking= pan. Bake 30 minutes or until crumbs are lightly browned.
TO FREEZE: Cool for 30 minutes at room temperature. Complete wrapping by= pulling paper up over top of food. Put edges of wrap together and fold= several times so paper lies directly on top of food. Fold ends of freezer= wrap over the top and seal with freezer tape. Label with name of food,= date of freezing, and last date the food should be used for best eating= quality (about 6 months). Freeze immediately for 10 to 12 hours before= removing packages from the pans.
TO HEAT FROZEN FOOD: Preheat oven to 375=B0 F. (moderate). Remove freezer= wrap. Place food in baking pan. Mix 1/4 cup fine breadcrumbs with 1= tablespoon melted butter or margarine for each pan. Sprinkle topping over= bean mixture in baking pan. Bake 1 1/2 hours or until edges are bubbly,= crumbs are lightly browned, and center is hot.