Ingredients
- 2 fistfuls sorrel leaves, about 3 cups, washed and spun dry
- 2 tablespoons butter
- 1/2 large sweet onion, chopped
- 5 to 6 small fingerling or new potatoes, cut into chunks
- 2 cups chicken or vegetable broth
- 1 egg, lightly beaten
- Salt and pepper, to taste
- Garnish: Sour cream or thick yogurt for hot or cold soup, or finely chopped cucumber and radish for cold soup
Directions
- Stack the sorrel leaves and cut into ribbons. Set aside.
- In a large heavy saucepan with a tight-fitting lid, heat the butter over medium heat. When the butter has melted, add the onion.
- Cook, stirring occasionally, until the onion is well-browned, about 10 minutes.
- Add the sorrel, potatoes, and broth. If the broth doesn’t cover the contents, add a little water.
- Bring to a boil, reduce heat to low, cover, and cook until potatoes are tender, about 15 minutes.
- When the potatoes are done, transfer half of the mixture to a blender or food processor (blenders give smoother results).
- Process carefully until the mixture is puréed and smooth. Repeat with remaining soup.
- Return the soup to the saucepan over low heat.
- Temper the egg by whisking it with about 1/4 cup of soup, then pour the egg mixture into the pan.
- Cook, whisking constantly, until the soup thickens, about 5 minutes. Do not boil.
- If serving hot, garnish each portion with sour cream or yogurt. If serving cold, cover the soup tightly and refrigerate for at least 4 hours before serving. Garnish with sour cream or yogurt and chopped cucumber and radish.