Wash the plums, cut them in half, stone them and then cut them into wedges.
Put the currant juice and sugar in a saucepan and bring to the boil. Add the plums and cook for about 5 minutes. Mix the cornstarch with a little cold water and use it to bind the grits.
Spread the groats on plates. Stir the yoghurt and a little cinnamon until smooth and pour on top. Sprinkle with muesli on top.