1 tbsp. Dijon mustard
1 (12 oz.) can corned beef
1 lb. sauerkraut, drained
1 (10 3/4 oz.) can condensed tomato soup (undiluted)
1/4 c. water
3 tbsp. pickle relish (not sweet)
4 (1 oz.) slices Swiss cheese, cut into 1/2-inch pieces
4 slices rye bread

Lightly grease an 8 or 9-inch square baking dish. Spread mustard evenly on one side of each bread slice. Cut bread into 1/2-inch squares. (You should have about 3 1/2 cups.) Scatter bread over bottom of prepared dish. Crumble corned beef over bread.

In a large bowl, mix sauerkraut, soup, water and relish until well blended. Spoon over corned beef; cover loosely with waxed paper. Microwave on High 6 to 8 minutes, rotating dish 1/2 turn twice until very hot. Place cheese on top to cover. Microwave, uncovered, on High 1 minute or until cheese is melted. Let stand 5 minutes.