¾ pound rhubarb, chopped (about 4 cups chopped rhubarb)
4 cups water
4 sprigs fresh mint
¼ cup turbinado sugar
2 pears, cored, peeled and chopped
Place the rhubarb, water, mint, and sugar in a medium saucepan over medium-high heat. Cover with a lid. Cook until the rhubarb is very soft, 8 minutes. Add the pears and cook for 2 to 3 minutes. Discard the mint.
Transfer to a blender and process into a soup. Let cool then refrigerate for 2 to 4 hours. Serve cold.