Step 1

Set an oven rack about 6 inches from the heat source and preheat the oven's broiler.

Step 2

Combine potatoes, vegetable broth, and salt in a multi-functional pressure cooker (such as Instant Pot®). Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 1 minute. Allow 10 to 15 minutes for pressure to build.

Step 3

Release pressure carefully using the quick-release method according to manufacturer's instructions, about 5 minutes. Unlock and remove the lid.

Step 4

Transfer potatoes carefully to an 8-inch square oven-safe deep dish. Combine 1 1/2 cups Cheddar cheese, cream, garlic powder, pepper, and nutmeg in the pressure cooker with the remaining liquid; select Saute function and cook until smooth and creamy, about 5 minutes. Pour sauce evenly over potatoes and sprinkle with remaining 1/2 cup Cheddar cheese.

Step 5

Broil in the preheated oven until golden, about 5 minutes.