Combine oats, milk and water in a deep bowl (so it wont overflow).
Microwave on high for 1 minute.
Remove from microwave; Add the banana, mashing and mixing it through the oat mixture to distribute it evenly.
Microwave on high for another minute and your porridge should be nice and thick and ready! If it is still a bit watery, microwave it on 80% power for another 20 seconds or so.
Add a couple toppings of choice for extra protein, healthy fats and staying power. My favourites are nut butter, ground nuts or toasted coconut for crunch.
To make on the stovetop, combine oats, water and milk in a small pot and bring to the boil; Add mashed banana and continue to cook on medium-high heat, or until the porridge is nice and thick and heated through. This should take 3-5 mins all-up.