Combine the salt, peppercorns, tarragon, dill, sugar, zest, juice, and vanilla in a medium-size mixing bowl. Mix well. Set aside.
Lay a piece of plastic wrap twice the size of the salmon on a flat surface. Cross another piece of plastic of the same size over the first piece horizontally. Place the salmon in the center of the pieces of plastic wrap, with the skin side down. Spoon the seasoning mixture over the top and sides of the salmon. Using your fingers, spread the mixture evenly over the salmon. No part of the flesh of the fish should be exposed. With the palm of your hand, gently press the mixture into the salmon.
Fold the two pieces of plastic wrap very tightly around the salmon, folding in the ends securely. Wrap the salmon a second time with another large piece of plastic. Place the wrapped salmon in shallow glass bowl and refrigerate for 24 hours.
Remove from the refrigerator and unwrap the salmon carefully. Discard the wrap and scrape off the seasoning mixture. Rinse the salmon under cold water for about 2 minutes to remove all of the seasoning mixture. Pat the salmon dry, wrap tightly in plastic wrap, and refrigerate until ready to serve.
To serve, remove 2 inches from the tail of the salmon. Slice the salmon, at an angle, into paper-thin slices. Serve with the caviar sauce and traditional garnishes.
Yield: 24 Hors Díoeuvre servings