Make the filling ahead of time and you'll need only a few minutes to go from shucking to eating.
Recipe information
Yield
Makes 24 servings
Ingredients
Preparation
Step 1
Pulse leek, shallot, and garlic in a food processor until finely chopped. Transfer to a small bowl; set aside. Pulse watercress in processor until finely chopped but not a paste. Transfer to a medium bowl; set aside.
Step 2
Melt butter in a large heavy pot over medium-low heat. Add leek mixture; season with salt and pepper and cook, stirring often, until translucent, 7-8 minutes. Increase heat to medium. Add watercress; cook, stirring often, until watercress is wilted and tender, 8-10 minutes. Stir in cheese, cream, and parsley. Season to taste with salt and pepper. Transfer to a medium bowl; chill until cold. DO AHEAD: Can be made 1 day ahead. Cover; keep chilled.
Step 3
Preheat broiler. Arrange oysters on half shells on a rimmed baking sheet. Dividing equally, spoon watercress mixture over oysters, spreading to cover completely.
Step 4
Broil until cheese is melted, top of watercress mixture begins to brown in spots, and oysters are just cooked through, 3-4 minutes. Serve immediately.
