Crockpot Au Gratin Potatoes and Ham

6 medium potatoes, peeled and sliced
1 medium onion, coarsely chopped
1 1/2 cups of cooked ham, cubed
1 cup of shredded American cheese
1 can of cream of mushroom soup
1/2 cup of milk
1/2 teaspoon of thyme leaves

In a crockpot layer 1/2 of the potatoes, onion, ham and cheese, repeat the layers.
In small bowl, combine the cream of mushroom soup, milk, and thyme and pour over top of the layers.

Cover and cook on the HIGH setting for 3 hours then reduce to the LOW setting and cook for 2 to 2-1/2 hours or until the potatoes are tender.