This isn't something I do often, as I prefer the texture of stovetop oatmeal. Add all of the ingredients to a bowl, mix well, and then microwave on HIGH for between 2-3 minutes. Use 1 cup liquid when doing this method and stop the microwave after a minute to stir and then heat for the remaining time. It's important to use a bowl with high sides as the water/milk will bubble up as it boils. You could also cover it with cling film with a few steam holes poked in it.