Place crushed ice in a shallow serving platter or on individual plates to create a cold bed for the oysters. Arrange lemon wedges around the edge and keep the platter in the refrigerator while you prepare sauces.

Shuck oysters

If oysters are not already shucked, scrub shells under cold water. Using an oyster knife and protective glove or towel, insert the tip at the hinge, twist to open, run the knife under the top shell to free muscle and discard top shell. Loosen the oyster from the bottom shell, keeping the liquor (briny liquid) in the shell. Arrange each oyster on the chilled crushed-ice bed, keeping them level so the liquor remains.

Serve immediately with lemon wedges and the prepared Cocktail Sauce and Champagne Mignonette on the side. Provide small forks and napkins.

Cocktail Sauce

In a small bowl, combine ketchup, prepared horseradish, fresh lemon juice, Worcestershire sauce, hot sauce, sea salt, and black pepper. Stir until smooth and taste; adjust horseradish for heat, lemon for brightness, or salt as needed. Chill the sauce at least 10 minutes to allow flavors to meld before serving alongside oysters.

Champagne Mignonette

In a small bowl, whisk together champagne, red wine vinegar, minced shallot, granulated sugar, sea salt, and black pepper until sugar and salt dissolve. Let the mignonette sit for at least 10–15 minutes at refrigerator temperature to mellow the raw shallot flavor and allow the vinegar and champagne to marry. Just before serving, stir in chopped chives if using.