1. Drain sauerkraut. Finely chop celery. Tear bread slices into small crumbs to make about 1 1/2 cups crumbs.
2. In small bowl, combine sauerkraut and brown sugar; set aside.
3. In medium-sized bowl, combine celery and water; cover bowl with large plate. Cook at high (100% power) 3 minutes or until celery is tender. Stir in ground beef, bread crumbs, milk, salt, pepper, and egg.
4. In 12" by 8" baking dish, pat half of ground-beef mixture into flat 9" by 6" oval. Evenly spoon sauerkraut mixture onto meat oval in baking dish to within 1/2 inch of edge. Top with Swiss cheese slices, folding slices to fit, if necessary.
5. On sheet of waxed paper, pat remaining meat mixture into a 9'/2" by 6'/2" oval; invert over cheese-topped meat mixture in baking dish; peel off waxed paper. With fingers, gently press edge of meat loaf to seal. Cover baking dish with waxed paper.
6. Cook at medium high (70% power) 20 minutes or until loaf is well done, rotating dish a half turn after 10 minutes. Let meat loaf stand 5 minutes, still covered.