Insert the trivet into the Instant Pot. Pour in 1 cup cold water inside the inner pot for a 3 or 6-quart instant pot and 1.5 cups of cold water into an 8 quart instant pot.
Inside a 7-cup heat-safe bowl, mix together the oats, 1 cup water, and 2 cups milk, and flaxseed. Please note that Pyrex is NO longer approved for using inside and instant pot.
Place the bowl on top of the trivet and put the lid on Instant pot.
Set Valve to "sealed" and set manual or time to 3 minutes on high pressure.
Allow to naturally release for 10 minutes before carefully releasing any additional steam by using a wooden spoon to turn valve to vent.
Remove bowl carefully from pressure cooker and then serve with desired toppings or allow to cool and store in fridge to reheat as needed.
When I first wrote this post, I suggested using an oven-safe glass dish, since then Pyrex has come out to say that their dishes are not safe in the Instant Pot, therefore I recommend this stainless steel bowl. A glass bowl may need an additional 3-5 minutes of cook time depending on its thickness. Total Time: 10 minutes to come to pressure + 3 Minutes Cooking Time + 5 Minutes Release= 18 total minutes. Liquid:
You need a total of 3 cups liquid to 2 cups oats for oats to cook properly. If you want your oats to be really loose, use an additional 1/2 cup of dairy or water.
You can use all water or all dairy. In my experience all water is incredibly bland and using all dairy/non-dairy as your liquid doesn't result in oats breaking down into a creamy texture.
It is important to note if you are using a high-fat dairy (like coconut cream or whole milk) you MUST use only half full-fat dairy products with half water so the fat in your dairy will not separate.
You will also need additional water under the trivet for the Instant Pot to come to pressure.
Preparing Oats directly in Inner Pot: Grease the inner pot with cooking spray and add 2 cups oats and 3 cups water directly to the inner pot. Feel free to add in seasonings such as cinnamon, or granulated sugar. Cook for 1 minute on high pressure and let the pressure release naturally.