Total time: 40 minutes
1 tablespoon butter
2 slices prosciutto, cut in thin ribbons
1 medium leek, finely chopped
1 shallot, minced
1/2 cup dry white wine
2 cups half-and-half
2 dozen oysters, shucked with oyster liquor retained
1 1/2 teaspoons minced tarragon for garnish, divided
1. Place the butter and the prosciutto in the bottom of a large saucepan over medium-low heat. Cook until the prosciutto softens and begins to darken, 3 to 4 minutes. Add the leek and shallot, and cook until they are soft and glistening, about 5 minutes. Add the white wine, and reduce to a syrup. (Recipe can be made to this point several hours in advance.)
2. Add the half-and-half, and bring just to a simmer over medium-low heat. When you see bubbles beginning to appear around the rim of the pan, add the oysters. Cook just until the oysters are plump and firm, about 3 minutes. Season to taste, if desired. Remove from the heat and ladle into well-heated soup bowls. Garnish each serving with one-fourth teaspoon chopped tarragon and serve immediately.
Each serving: 171 calories; 5 grams protein; 8 grams carbohydrates; 0 fiber; 12 grams fat; 7 grams saturated fat; 46 mg. cholesterol; 178 mg. sodium.