Combine the oats, water, and almond milk in a small saucepan and bring to a boil over medium heat.
Reduce heat to low and simmer gently, stirring occasionally, for about 5 minutes until the oats are tender and the mixture thickens.
While the oats cook, thoroughly mash the ripe banana with a fork in a bowl until mostly smooth.
Stir the cooked quinoa, mashed banana, blueberries, ground chia seeds (or flax meal), diced walnuts, and cinnamon into the pot with the cooked oats.
Cover the pot and let the mixture sit off the heat for 2 minutes to allow flavors to meld, then serve.
