Add broth, water and butter to the Instant Pot. Add cut cabbage. Season with salt, pepper, and garlic powder.
Close lid and lock. Make sure valve is switched to sealing.
Select MANUAL mode (high pressure) for 7 minutes. Once cooked, switch valve to venting and manually or quickly release the pressure.
Once the float valve has dropped, carefully remove the lid. Use a slotted spoon to remove the cabbage from the pot. Season with additional salt and pepper to taste.