2 tablespoons unsalted butter
1/4 pound French baguette, crusts removed, bread cut into 1/2-inch dice
2 ounces smoky bacon, cut into 1/4-inch dice
1 medium onion, cut into 1/4-inch dice
1/2 cup dry white wine
1 1/2 quarts chicken stock or canned low-sodium broth
1 garlic clove, minced
1/2 pound Yukon Gold potatoes, peeled and cut into 1/4-inch dice
Salt and freshly ground pepper
1 1/2 tablespoons fresh lemon juice
1/4 teaspoon finely grated lemon zest
3 tablespoons crème fraîche or heavy cream
1/2 pound sorrel, stems discarded, leaves coarsely chopped
Melt 1 tablespoon of the butter in a large skillet. Add the diced baguette and cook over moderately low heat until browned on the bottom, about 3 minutes. Stir the croutons and cook until crisp all over, about 2 minutes longer. Transfer to a plate to cool.
Melt the remaining 1 tablespoon of butter in a large saucepan. Add the bacon and cook over moderately low heat until lightly browned, about 4 minutes. Add the onion and cook until softened, about 7 minutes. Add the wine and simmer until almost evaporated, about 4 minutes. Add the stock and garlic and bring to a simmer. Add the potatoes, season with salt and pepper and cook until tender, about 10 minutes. Stir in the lemon juice and zest and the crème fraîche and simmer for 2 minutes. Remove from the heat and stir in the sorrel. Season with salt and pepper. Ladle the soup into bowls and serve; pass the croutons at the table.
Make Ahead: The croutons can be made a day ahead. Store in an airtight container. The soup can be made without the sorrel and refrigerated overnight. Bring to a simmer and add the coarsely chopped sorrel just before serving.
bacon recipe courtesy of: Eberhard Müller, "Cooking Seasonal: Spring Dishes from Eberhard Müller," Food & Wine, April 2001