Country Ham and Potato Salad

• 24 ounces red-skinned potatoes (about 3 medium), unpeeled, cut into 1/4-inch-thick slices
• 1 cup sour cream
• 6 tablespoons coarse-grained Dijon mustard
• 8 ounces ham, cut into 1/2-inch cubes
• 1/3 cup chopped onion

Cook potatoes in medium pot of boiling salted water until just tender, about 6 minutes. Drain, reserving 2 tablespoons cooking liquid.

Whisk cream, mustard and reserved potato cooking liquid in large bowl to blend. Add potatoes to dressing and toss to coat. Refrigerate until slightly cooled, about 5 minutes. Mix ham and onion into salad. Season salad to taste with salt and pepper.