01 -
In a saucepan, combine the chopped rhubarb, elderflower cordial, water, and sugar. Bring to a boil over medium heat.
02 -
Reduce heat and simmer for about 15 minutes, or until the rhubarb is tender.
03 -
Remove from heat and let cool slightly. Then, blend the mixture until smooth using an immersion blender or regular blender.
04 -
Chill the soup in the refrigerator for at least 2 hours.
05 -
Before serving, swirl in the plain yogurt for a creamy finish.
06 -
Serve cold, garnished with fresh mint leaves.