1. Prepare: Place a trivet and steamer basket into the pressure cooker. Add 1 1/2 cups water, squash, carrots, and onion. Close, seal, and place on high.
4. Release: Once all pressure is released, remove the lid and let sit for 5+ minutes (remember it’s hot).
5. Let cool: Once all pressure is released remove the lid and let sit for 5+ minutes (remember it’s hot).