Carefully cut the spaghetti squash in half lengthwise. Using a spoon, scoop the seeds and some of the flesh out of the middle.
Pour water in the bottom of your instant pot. Place a steamer basket or the wire rack that came with the instant pot at the bottom. Place the spaghetti squash on top.
Secure Instant Pot lid, set the valve to the “sealing” position, and pressure cook on high for 7 minutes.
When the timer is up, switch the valve to the “venting” position and manually release the pressure. When the pressure is fully released, remove the lid.
Use a fork to scrape the strands of spaghetti squash out of its skin. Be careful when handling the hot squash.
Serve spaghetti squash as desired.
Notes
Make sure your lid fits securely on your Instant Pot when closed. If needed, you might have to set the spaghetti squash in the pot sideways for the lid to fit on. Or, cut it into quarters instead of halves or cook 1/2 of the squash at a time.
Be very careful when manually releasing the pressure. The steam can burn you, so be sure to keep your hands and face away from the valve.
6 qt. Instant Pots are slightly too small to fit both halves of a 4 pound squash. If needed, you may need to cook the spaghetti squash on its side, cut it into quarters, or cook 1/2 squash at a time. I typically will do this and don't mind it - it cooks so fast anyway!
Be careful when releasing the pressure valve as the steam can burn you.