Combine water, oats, apple, cinnamon, salt, and nutmeg in a multi-functional pressure cooker. Close and lock the lid. Seal vent. Select Manual function; set timer for 5 minutes. Allow 10 to 15 minutes for pressure to build.
Release pressure using the natural-release method, about 10 minutes. This is important because if you release through the vent, the oats can jam up the vent.
Release remaining pressure naturally.
Store for 1 week and reheat portions as desired on the stove in the microwave when you are in a rush
Add-ons
Nut milk of choice to add creaminess
½ tbsp ground flaxseeds or ground psyllium husk (great prebiotic!)
Nut butter ½-1 tsp or 4-6 crumbled walnuts if you like a crunch
Manuka honey ½ tsp (added immune benefit)
Frozen berries (¼ cup wild blueberries are our favourite)