600 g peeled rhubarb (2 stems), cut into 1 cm pieces
200 g raspberries
300 ml water (for stirring in the potato flour)
4 peace of rhubarb, sugar 1 heaped table spoon potato starch (this is for a runny wedge, but a few spoonfuls more for a thicker one)
Cooking:
Bring the water to the boil in a saucepan. When the water starts to boil, add the raisins. Cook for 5 minutes, then add the sliced rhubarb and sugar. Cook everything together for another 2-3 minutes. Add the raspberries (they will dissolve as they boil).
Dissolve the potato starch in the cold water. Wait for the first bubble in the pot and add the cold water with the starch, stirring slowly. Cook, stirring constantly, over a low flame for a few more minutes. The knisel will thicken slowly and will acquire the right consistency. Drink warm or chilled – both are delicious.