Salmon and Spinach Terrine with Cucumber-Dill Sauce

This Side recipe was published in 'Martha Stewart Living Radio Thanks giving Hotline Recipes 2010 - p34'.

Gorgeous and elegant, this is a first course for your finest dinner party. For a fancy appetizer, it comes together very quickly, and has the added attraction of being totally make ahead. It can also be served as a spread for a crowd at a cocktail party buffet.

Makes 12 servings

Make Ahead: The terrine must be chilled at least 4 hours or overnight; it can be made up to 2 days ahead of serving. The sauce can be made up to 1 day ahead.

Ingredients for TERRINE:
• 1 tablespoon unsalted butter
• 3 tablespoons finely chopped shallots
• 1⁄2 cup dry vermouth
• 20 ounces skinless salmon fillets, cut into pieces
• 4 ounces sea or bay scallops
• 1⁄2 cup fresh bread crumbs (make in a food processor or blender)
• 1 large egg
• 1 and 1⁄4 teaspoons salt
• 1⁄4 teaspoon freshly ground white pepper
• 1⁄8 teaspoon hot red pepper sauce
• 1 and 1⁄2 cups heavy cream
• One 10-ounce package frozen chopped spinach, thawed, squeezed well to remove liquid

Ingredients for CUCUMBER-DILL SAUCE:
• 1 medium cucumber, peeled, seeded, and cut into 1⁄4-inch dice
Salt
• 3⁄4 cup sour cream
• 2 tablespoons milk
• 2 tablespoons chopped fresh dill
• 1⁄8 teaspoon freshly ground white pepper
• Fresh watercress or dill sprigs, for garnish

Preparation:
1. Preheat the oven to 325°F. Lightly oil an '8 and 1⁄2' x '4 and 1⁄2' x '2 and 1⁄2'-inch loaf pan. Line the bottom of the pan with waxed paper.

2. To make the terrine, in a small saucepan, melt the butter over medium-low heat. Add the shallots and cook until softened, about 2 minutes. Add the vermouth and cook until reduced to 1 tablespoon. Remove from the heat and cool.

3. In a food processor fitted with the metal blade, pulse the salmon and scallops until finely chopped. Add the shallot mixture, bread crumbs, egg, salt, white pepper, and hot pepper sauce. With the machine running, gradually add the heavy cream. Transfer 1 cup of the purée to a medium bowl and stir in the spinach.

4. Spread half of the salmon purée in the loaf pan, then spread the spinach purée over the salmon. Top with the remaining salmon purée. Cover with a piece of buttered waxed paper, buttered side down.

5. Place the loaf pan in a larger roasting pan and place in the oven. Add enough hot water to the roasting pan to come 1⁄2 inch up the sides of the loaf pan. Bake until an instant-read thermometer inserted in the center of the terrine registers 140°F, about 1 hour. Cool completely in the pan on a wire rack. Remove the waxed paper from the top of the terrine, then invert and unmold the terrine and remove the waxed paper from the bottom. Tightly wrap the terrine in plastic wrap. Refrigerate at least 4 hours or overnight.

6. Meanwhile, make the sauce: In a small bowl, toss the cucumber with 1⁄2 teaspoon salt. Let stand for 30 minutes. Place in a colander and rinse well. Pat dry with paper towels. Squeeze the cucumber to remove excess moisture.

7. In a medium bowl, mix together the cucumber, sour cream, milk, dill, and pepper. Season with salt to taste (you may not need very much, as the cucumber has already been salted). Cover with plastic wrap and refrigerate until chilled, at least 1 hour.

8. Cut the terrine into 12 slices. Divide slices among 12 dinner plates. Spoon equal amounts of the sauce alongside each slice. Garnish with the watercress. Serve immediately.