Tarragon-Roasted Salmon

2 large lemons, thinly sliced
1 whole salmon (51⁄2 pounds), cleaned and scaled
2 tablespoons olive oil
1⁄2 teaspoon salt
1⁄2 teaspoon coarsely ground black pepper
1 large bunch tarragon
1 small bunch parsley
Caper Sauce (see below)
lemon wedges

1. Preheat oven to 450°F. Line jelly-roll pan with foil. Arrange one-third of lemon slices in row down center of pan.
2. Rinse salmon inside and out with cold running water; pat dry with paper towels. Rub outside of salmon with oil. Place salmon on top of lemon slices. Sprinkle cavity with salt and pepper. Place tarragon and parsley sprigs and half of remaining lemon slices in cavity. Arrange remaining lemon slices on top of fish. Roast salmon until just opaque throughout when knife is inserted at backbone, about 40 minutes.
3. Meanwhile, prepare Caper Sauce.
4. Carefully remove lemon slices and peel off skin from top of salmon; discard. Using two wide spatulas, transfer salmon to cutting board.
5. To serve, slide cake server under front section of top fillet and lift off fillet; transfer to warm large platter. Slide server under backbone and lift it away from bottom fillet; discard. Slide cake server between bottom fillet and skin and transfer fillet to platter. Serve with lemon wedges and caper sauce. Makes 10 maindish servings.

Caper Sauce
In medium bowl, mix 3⁄4 cup sour cream, 1⁄2 cup mayonnaise, 1⁄4 cup milk, 3 tablespoons capers, drained and chopped, 2 tablespoons chopped fresh tarragon, 1⁄2 teaspoon freshly grated lemon peel, and 1⁄8 teaspoon coarsely ground black pepper until blended. Cover and refrigerate until ready to serve, up to two days. Makes about 12⁄3 cups.