Slow Cooker Ham and Scalloped Potatoes

INGREDIENTS

• 1 cup water
• 1/2 teaspoon cream of tartar
• 5 potatoes, thinly sliced
• 1 cup chopped onion
• salt and ground black pepper to taste
• 2 cups milk
• 1/4 cup all-purpose flour
• 1 cup shredded Cheddar cheese
• 2 cups cubed smoke ham