Scalloped Potatoes with Ham

I realize I am a couple days behind with most things that I do, so I figure it is okay to post my crock pot recipe in the month of June. Thanks Tara for the recipe, it is one of our favorites so I hope you don't mind if I use it.

6 cups raw potatoes cut into small cubes
1 med. onion, minced
1 tsp. salt
1/2 lb. cooked ham, cubed
1 1/2 cup shredded cheddar cheese
4 Tbsp. butter
4 Tbsp. flour
1 tsp. salt
2 cups milk

Layer potatoes, onion, 1 tsp. salt and ham into slow cooker. Melt butter in saucepan. Stir flour and 1 tsp. salt. Cook until bubble. Gradually add milk. Cook until smooth and thickened. Add cheese and stir until melted. Pour over potato-ham mixture, stirring lightly. Cover. Cook on low 6-7 hours or high 3-4 hours.