Potato Spinach Soup

4 medium potatoes, diced
1 onion, chopped finely
1 cup chopped ham
4 cups chicken broth
1/2 teaspoon dry mustard
1/2 teaspoon salt
pepper to taste
1 package (10 oz.) frozen spinach, thawed and squeezed dry
1 cup shredded Swiss cheese

Combine first 7 ingredients in crock pot. Cover and cook on low 7 to 8 hours, until potatoes are tender.

Add spinach and continue cooking on high for 15 to 20 minutes.

Serve with shredded cheese sprinkled on top, if desired.