Little Neck Clams on the Half Shell with Champagne-Caviar Mignonette

Ingredients

• 24 fresh little neck clams, shucked and on the half shell
• 4 cups finely crushed ice
• 1/4 cup plus 1/8 teaspoon kosher salt
• 2 teaspoons finely crushed white pepper

• 1/4 cup champagne vinegar
• 2 tablespoons olive oil
• 2 tablespoons finely chopped shallots
• 1/4 ounce caviar