This northern European sour soup makes a rich, wonderful, and full-bodied starter. The acidity of lemon complements the richness and near-sweetness of the stock, and the combination is simply amazing. For Greek egg-lemon soup, see the preceding recipe.

　　

Ingredients

makes 4 servings

　　6 cups homemade jus rôti or chicken stock (page 163 or 160) or the best stock you can find

　　1 large lemon, or more to taste

　　2 egg yolks

　　2 tablespoons flour

　　1 cup sour cream

　　1 cup croutons (page 580)

　　

Step 1

Put the jus rôti in a medium saucepan and bring it to a boil over medium-high heat; turn off the heat as soon as it boils. Meanwhile, grate the zest of the lemon. Juice the lemon.

　　

Step 2

Use a whisk, an electric mixer, or a blender to combine the egg yolks, flour, and sour cream until smooth. Continue to mix while slowly adding the jus rôti.

　　

Step 3

Stir in the grated lemon zest and lemon juice. Transfer everything back to the saucepan and reheat the soup gently; taste and adjust the seasoning (you might like to add more lemon juice), then garnish with the croutons and serve.

　　The Best Recipes in the World by Mark Bittman. © 2005 by Mark Bittman. Published by Broadway Books. All Rights Reserved.MARK BITTMAN is the author of the blockbuster The Best Recipes in the World (Broadway, 2005) and the classic bestseller How to Cook Everything, which has sold more than one million copies. He is also the coauthor, with Jean-Georges Vongerichten, of Simple to Spectacular and Jean-Georges: Cooking at Home with a Four-Star Chef. Mr. Bittman is a prolific writer, makes frequent appearances on radio and television, and is the host of The Best Recipes in the World, a 13-part series on public television. He lives in New York and Connecticut.