Creamy Nachos

1 small pkg. Mild Mexican velveeta
1 lb. Hamburger
1 small onion- chopped
1 can Ranch style beans- drained
1 can Rotel- drained
8 oz. Sour cream

Brown hamburger and onions. Put all ingredients in the crock pot and cook on low 4 to 6 hours. Serve with tortilla chips.