Aunt Janice's Reuben Dip

1 (16 ounce) can sauerkraut, drained and pressed dry
1 small onion, finely chopped
1/2 pound corned beef
1 cup mayonnaise
1 1/2 cups sour cream
3 tablespoons prepared horseradish
1 1/2 cups shredded Swiss cheese

Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 1-quart baking dish.
In a blender or food processor, place sauerkraut, onion and corned beef. Process until smooth.
Place sauerkraut mixture in the baking dish, and mix with mayonnaise, sour cream, prepared horseradish and Swiss cheese.
Bake in the preheated oven 30 to 40 minutes, or until bubbly and lightly browned.