Japanese Knotweed Soup

 

1 T. unsalted butter

1/2 cup (80 g) finely chopped shallots

4 cups (about 340 g) skinned and sliced knotweed, joints discarded

2 small potatoes, peeled and thinly sliced

4 cups (1 L) hot chicken or vegetable stock

Salt

Freshly ground black pepper

Heavy cream, for serving (optional)

 

In a pot, melt the butter until it foams. Add the shallots and cook gently until they are translucent. Add the knotweed and cook, stirring, for 2 to 3 minutes until the color of the knotweed changes from fresh green to drab khaki. Add the potatoes and the stock and cook until the potato slices are tender, about 10 minutes. Allow the mixture to cool, then puree it in batches in a blender. Strain each batch through a fine-mesh sieve into a bowl. Return the soup to the stove and heat until simmering, then season to taste. A swirl of cream before serving is never a bad idea.