In a small bowl or measuring cup, add the miso, honey and the boiling water. Whisk until the mixture is cloudy and the miso and honey are fully dissolved.
Put a skillet or pan on medium low heat. Add the diced apple, cinnamon and 1/4 cup of the water/miso mixture. Cover and let the apples stew for 1-2 minutes, stir and add more of the water mixture as needed. Cook another 2-3 minutes or until the apple is soft.
Sprinkle the lemon juice over the apple, move the apple to a bowl and set aside.
Using the same pan, add the oats, chia seeds and the remainder of the water. Bring this mixture to a very low simmer. Let the oats simmer for 4-5 minutes or until thick, and then turn off the heat.
Add the egg whites one at a time to the oatmeal, whisking constantly. You want to whisk at a quick pace to make sure that the egg whites emulsify into the oats like a custard, instead of curdling into scrambled eggs in the mixture. This might take some practice, but my big tips are to whisk quickly and make sure your oats aren't too hot!
Add the stewed apple to the oats and mix again. Pour the oats into a serving bowl.
On a cutting board to the side, split open the dates and stuff them with the crushed pistachios.
Add the dates to the top of the oatmeal.
Drizzle with optional toppings (or anything else you prefer!) and serve warm.