Puree all of the spicy cocktail ingredients in a blender. In a medium bowl, spoon the cocktail sauce and vodka over the oysters, clams, peppers, and cilantro and mix gently. Chill.
Whisk together ingredients for chipotle vinaigrette. Divide seafood mixture between two large martini glasses and drizzle vinaigrette over each.
Garnish with lime wedges, pearl onions and strips of serrano chile.
c.1996, M.S. Milliken & S. Feniger, all rights reserved