Peel the rhubarb thoroughly and then cut the stalks into 3 cm pieces.
Sprinkle with 100 g of sugar in a large bowl and leave to juice for 2-3 hours, stirring frequently.
Transfer the rhubarb to a saucepan and cook on the lowest setting with lemon zest, cinnamon and a little water if necessary.
Sweeten the mixture with a little sugar to taste. Remove the lemon zest and cinnamon stick from the pot and let the compote cool.
Garnish with a few fresh mint leaves before serving.
Cooking the compote takes only a few minutes, the rhubarb should not become too soft if possible.