Peel the rhubarb and cut it into cubes. Cook with sugar, water and lemon juice for approx. 10 minutes or until the rhubarb is soft and has a light pink colour. If this isn't the case, add a handful of raspberries.
Put cling foil into a bowl or on a plate and pour the rhubarb into it. Freeze for at least 4 hours.
Blend with yogurt and lemon zest. Refreeze until you need the icecream or serve it immediately.
Tipps
You can make the rhubarb icecream vegan by not using any yogurt or substituting it with vegan yogurt-alternatives. Icecream-lovers have to try basic vanilla icecream (no icecream maker) and vegan coconut-caramel-chocolate-icecream as well!