Wash and peel potatoes. Slice very thinly. Add to a steamer basket. Pour water into Instant Pot. Drop basket in. Pressure cook 1 minute. Vent and remove the lid. Remove the basket.
Spread half the potatoes in a pot-in-pot dish. Combine salt, peppers, garlic powder and nutmeg in a bowl. Pour half over potatoes. Pour half the cream on top. Sprinkle half the cheese. Repeat.
Cover with foil. Place the pan into the pot on a trivet. Pressure cook 10 minutes then vent. Remove foil and use an air fryer lid to brown the top for 4-6 minutes at 400F.