Rinse millet in a sieve. Then transfer it to a medium pot and add milk and salt.
Bring the mix to a boil over medium-high heat, then lower the heat to medium and cook millet, stirring occasionally, for about 10 minutes.
Stir in the chopped apple, honey and cinnamon and cook for another 5 minutes until millet expands and is tender enough to eat. Add more milk if needed to make the porridge creamier.
Serve warm and sprinkle with more cinnamon and some chopped nuts if desired.
Notes
Millet can be cooked in water, but I prefer milk for more flavor. You can use whole milk or a dairy free alternative like almond milk or soy milk. If you find that the apple is sweet enough, skip the addition of honey.