As served at the White Barn Inn, this is a real chef's special. Not only does it call for champagne, it 's a last-minute assemblage of many separately prepared parts. The garnish alone involves several steps and, at the restaurant, minute quantities of four different vegetables (potatoes, celery root, beets, and carrots). Because the dish itself – a glorified stew, really – is both fairly simple and seriously delicious, we've streamlined the presentation for this home-kitchen version.
1 tablespoon minced shallots
In a wide thick-bottomed, shallow, nonreactive pan, combine minced shallots, thyme, wine, and a pinch each of salt and pepper. Bring liquid to a boil, add clams and mussels, cover, and cook only until shell s open, 2 to 3 minutes. Set the cooked bivalves aside, covered. Strain the liquid through cheesecloth to remove sand, and set aside. In a nonreactive saucepan over low heat, briefly wilt the diced shallots and garlic in 1 teaspoon of the butter; don't let them take color. Add 1 cup of the reserved clam and mussel liquid, raise heat to high, and reduce the liquid by half. Add the cream and half the champagne. Reduce again to a sauce that coats a spoon. Season with salt and pepper, strain, and set aside. In a small skillet melt remaining teaspoon of butter over medium heat. Add carrots and cook just until tender. Remove carrots with a slotted spoon and set aside in a warm place. Add beets to pan, stir to coat with butter, and set aside in a warm place. Sprinkle the salmon and scallops lightly with salt and pepper and place in a wide, shallow, nonreactive pan. Add the remainder of the champagne and bring gently to a boil over medium heat. Immediately add saffron, reserved mussels and clams, and cream sauce. Bring stew back to a boil, being careful not to break up the fish. It should be just cooked at this point; don't worry if there 's a bit of translucency at the center; heat will finish the cooking. Taste and add salt and/or pepper if needed. To serve, put a quarter of the rice in a warmed soup bowl. Ladle the stew on top and garnish with the vegetables (and dill, if desired).