Mix the following and put in a crock pot…. 

Approx. 3/4 lb corned beef sliced into small pieces – (I use (6) 2 oz Buddig brand packages – I buy mine at Walmart)

8 oz shredded swiss cheese

8 oz shredded cheddar cheese

1 large jar glass sauerkraut (drain juice)

3/4 cup mayonnaise or thousand island dressing

I usually microwave the entire mixture for a few minutes and stir it before I put it into the crock pot.