Step 1In a food processor or blender, blend the tuna, anchovies, lemon juice and capers until smooth. Continue processing and pour the olive oil in a steady thin stream, through the feeder tube, until the consistency of a thick sauce. Transfer to a bowl, cover with plastic wrap and chill 1 hour. Makes about 1 cup.
Step 1Mix together the sour cream, mayonnaise, lemon juice, onion, capers, basil and salt and pepper to taste in a bowl. Cover with plastic wrap and refrigerate 1 hour. Makes about 1 cup.
Step 1Wrap the filets in cheesecloth and tie with string.
Step 2Place the bay leaves, peppercorns and pickling spice in a separate square of cheesecloth, tying the ends with string to form a pouch.
Step 3In a heavy pot, bring the water, onion, carrots, celery, white wine vinegar, salt, sugar and bay leaf mixture in the pouch to a boil. Simmer for 30 minutes; remove the pouch from the broth. Gently lower the cheesecloth-wrapped salmon into the simmering broth and cook 3 minutes. Cool the fish in the broth to room temperature, about 45 minutes.
Step 4When cool, remove the fish from the broth, unwrap it and transfer to a serving plate using a large spatula. Serve with the two sauces, garnished with lemon slices.