Place half of the milk, a peeled and chopped banana, and optionally a pinch of turmeric in a blender. Blend until smooth. Use a very ripe banana for added sweetness. Transfer to a saucepan.

Pour the remaining milk into a glass. Add the starch and optionally sweetener (especially if the banana isn't very sweet). Mix thoroughly to achieve a smooth consistency without lumps.

Place the saucepan with the blended banana on medium heat. Warm up the mixture, constantly stirring with a kitchen whisk or fork.

As the saucepan's contents begin to simmer lightly, reduce the heat and slowly pour in the milk with the added starch (stir again just before pouring to ensure nothing settles at the bottom), stirring continuously at a medium pace with a kitchen whisk or spoon. Once all ingredients are combined, continue stirring and increase the heat to medium. Keep stirring the pudding until it boils and thickens. After a moment, turn off the heat. The pudding should have no lumps. If lumps appear, try to eliminate them by more thorough mixing and mashing with a kitchen whisk or spoon.

Transfer the ready pudding to a bowl. Enjoy warm or cold.