Wash the grapes, dry them, and cut them in half (remove the stems).
Rinse the millet thoroughly under running water or place it in a container, cover with water, stir, and drain repeatedly until the water runs clear.
Put the rinsed millet in a pot and add the soy milk (or other plant-based milk) and water in a 1:1 ratio (water:ingredients). Cook over low heat until soft and thickened, about 10-15 minutes. Stir occasionally. If necessary, add a bit more water during cooking.
At the end, add the sweetener and mix well.
Transfer to a bowl. Top with grapes.