From one of my fav cooking blogs: http://lizscookingblog.blogspot.com/
1/3 pound deli corned beef, sliced into very thin strips
1 can sauerkraut, drained
2 cups shredded Swiss cheese
1/2 cup Thousand Island salad dressing
1/4 cup prepared horseradish, regular or creamy
cocktail rye bread, toasted
Mix all ingredients and pour into pie plate or shallow baking dish. Bake at 325 degrees until bubbly. Serve with toasted cocktail rye bread.
Substitute turkey for the corned beef to cut the fat and cals, and make it a Rachel Dip!