In a medium size pan, heat the oats, milk, water, and salt over medium heat.
Once the mixture begins to simmer, approximately 5-6 minutes, stir in the sliced banana. Continue to stir, almost whipping, until the banana breaks down and the mixture thickens and becomes creamy, about another 3-4 minutes.
As I have mentioned in many of my oatmeal recipes, I really like adding the banana because it adds so much volume to the oats. Add the vanilla extract, peppermint extract, and stevia, and stir until incorporated.
Pour into a serving bowl, dust with cocoa powder, sprinkle with mini chocolate chips, and garnish with the mint leaves.