This recipe is for steel cut oats; other oats such as rolled oats or quick cook oats will require different cooking times!
A note on the water ratio:
Depending on how thick or thin you prefer your oatmeal, adjust the water ratio accordingly. I find anywhere between 2 to 3 cups of water per 1 cup of oats works well. I like my oatmeal a bit runnier, so I use 3 cups of water. You can also substitute some of the water for milk, almond milk, oat milk, etc. I use 1/2 cup of almond milk and 2 1/2 cups of water and find it works well. Be careful if you are using too much milk as it can burn in the instant pot!
I would recommend at least 20 minutes of natural release. Leaving the oatmeal in the pot longer is perfectly fine too!