Nettle soup has long been eaten as a spring tonic. Look for nettles at farmers' markets throughout the spring and early summer. Nettles are covered with nearly invisible sharp hairs that can sting painfully, but cooking renders them harmless. Giana Ferguson, the artisanal cheese maker who gave us this recipe, advised us to wear rubber gloves when handling nettles. Wash them well, and use only the tips and tender leaves, snipping them off with kitchen shears.
- 2 Tbsp. butter
- 1 medium yellow onion, peeled and chopped
- 7 cups duck stock or 5 tbsp. glace de canard dissolved in 6 1⁄4 cups hot water
- 2 medium russet potatoes, peeled and chopped
- 1 leek, trimmed, white and light green parts only, washed and chopped
- 3 cups tightly packed, young nettle tips and tender leaves (about 1⁄4 lb.)
- Salt and freshly ground black pepper
- 2 Tbsp. fresh lemon juice
Melt butter in a medium pot over medium heat. Add onions and cook, stirring often, until softened, 6–8 minutes. Add the duck stock, potatoes, and leeks and bring to a simmer. Reduce heat to medium-low and simmer gently until potatoes and leeks are soft, about 15 minutes. Add the nettles, season to taste with salt and lots of pepper, increase heat to medium, and cook until nettles are tender, 5–7 minutes.
Working in batches, carefully purée the hot soup in a blender until smooth, 2–3 minutes per batch. Pour puréed soup into a clean medium pot and reheat. Add lemon juice and adjust seasonings. Stir in some cream before serving, if you like.