1. Place the shrimp and scallops in 3 quarts of boiling water. When the water returns to a boil, drain the seafood and refresh under cold running water.

2. Slice the shrimp in half lengthwise, and slice the scallops horizontally into 2 or 3 rounds. (The seafood can be prepared up to 1 day ahead. Cover and refrigerate.)

3. In a bowl large enough to hold the seafood, make the vinaigrette. First mix together the lemon juice and mustard. Add the oils and whisk well. Season with the salt and pepper and stir in the chopped herbs. Refrigerate. (This can be done ahead and taken out of the refrigerator when ready to assemble the salad.)

4. To serve, arrange the Bibb lettuce on the serving plates. Whisk the vinaigrette until it is smooth, and toss the seafood in it. Either simply mound the seafood in the center of each plate, or arrange each plate by overlapping the shrimp and scallops to form a circular design.

* If more than one herb is available, use 1 tablespoon of each.