1. Scrub oysters well. Combine oysters and apple cider in a 2-qt. saucepan and bring to a boil. Steam oysters, covered, over moderately high heat until they just open, checking occasionally after 3 minutes and transferring to a plate as they open. (Reserve steaming liquid and discard any unopened oysters.) Chill oysters, loosely covered, until cool, about 30 minutes.
2. While oysters are chilling, pour oyster steaming liquid through a paper towel-lined sieve into a bowl to remove any grit. Stir 2 tablespoons strained liquid together with remaining ingredients and salt to taste. Discard remaining strained liquid.
3. Remove flat half of oyster shell and loosen oyster with a sharp knife. Put oysters in rounded half of shell. Arrange on plates and spoon sauce over oysters.

Yield: 2 servings