Preheat oven to 400F. Slice potatoes into ¼ -inch thick pieces. (A mandolin or food processor will ensure even thickness)

In a large bowl, whisk together sour cream, half and half and soup mix. Add potatoes and ½ cup shredded cheese. Stir to evenly coat.

Transfer to a 2.5 to 3-quart casserole dish or pan. Distribute mixture evenly in the pan, then cover pan with lid or foil.

Bake at 400F for 50-55 minutes. Check with a fork to verify the potatoes are tender.

Remove lid or foil and sprinkle the remaining shredded cheese evenly on top of the potatoes.

Return to oven and bake 10-15 minutes until the top is golden brown.

Remove from oven and allow to rest 10 minutes before serving.