Layer half each of first 4 ingredients in a 5-quart slow cooker. Sprinkle with salt and pepper; repeat layers with remaining potato, onion, ham, and cheese.
Stir together soup and 3/4 cup water; spoon over potato mixture.
Cook, covered, on LOW 7 to 8 hours. Sprinkle with chives, if desired.
Find recipes with ingredients that you have on hand.