Blend all ingredients in a large bowl (the mustard will blend in more easily if mixed with a small amount of liquid from the beans). Pour into greased casserole (use butter or margarine), and bake, covered, 1 1/2 to 2 hours. If too juicy, remove lid for last of baking. This recipe multiplies very successfully to feed a crowd. Note: Canned tomatoes may be used, but if so, they should be seasoned with a little chopped onion, green pepper, and celery sauteed in butter or margarine. Using the already seasoned stewed tomatoes is the easy way.