In a small bowl, whisk the egg thoroughly.
In a medium microwave safe bowl (use a good sized bowl so it doesn’t overflow in the microwave), stir together the water, oats, chia, and salt. Microwave for about 2 minutes, then give it a stir and microwave for 30 more seconds (you want it to still be a little bit liquidy so that eggs can easily mix in, but not watery - see video).
Immediately (while the oats are still piping hot) slowly pour the egg into the oats while whisking the oats constantly. Stir in the nut butter, cinnamon, and any other mix-ins.
Add sweetener to taste and top with desired toppings.
These oats are delicious both warm and cold the next day.