Season the salmon lightly with salt, brush the top with a little melted butter, and immediately sprinkle evenly with the crushed pepper and chopped ginger. Drizzle the remaining butter over. If you wait too long, the butter will harden and the mixture won't stick. Refrigerate, covered, until needed.
Preheat the oven to 500 degrees F.
Prepare the sauce: In a small saute pan, melt 2 tablespoons butter until foamy. Over medium heat, saute the shallots and garlic until the shallots are translucent, 2 to 3 minutes. Stir in the tomato and cook 1 or 2 minutes longer. Pour in the wine and vinegar, turn up the heat a little, and reduce until 1/2 cup remains. Pour in the water and reduce by half. Strain into a clean pan. Finish the sauce by whisking in the remaining 4 tablespoons butter and season, to taste, with salt and pepper. Keep warm.
Brush some olive oil over a baking tray large enough to hold the salmon slices in 1 layer and arrange the salmon on the pan. Roast until medium, about 10 minutes. The salmon should be cooked on the outside, but still moist and slightly underdone on the inside.
Presentation: Divide the sauce amoung 4 warm dinner plates. Spoon equal amounts of celery root puree in the center of each plate and place 1 piece of salmon on the top.
1 celery root (about 1 1/2 pounds), peeled, trimmed, and cut into 1-inch cubes
1 or 2 small baking potatoes (about 4 ounces), peeled and cut into 1-inch cubes
1 teaspoon salt
1/2 cup heavy cream
2 tablespoons (1-ounce) unsalted butter
Freshly ground white pepper
Place the celery root and potato in a medium saucepan and cover with cold water. Season with salt and cook until soft, 15 to 20 minutes.
Drain the water and return the celery and potato to the pan. Pour in the cream and simmer over medium heat, stirring occasionally to prevent sticking, until thickened and most of the cream is absorbed, about 10 minutes.
Remove from the heat, stir in the butter, and season with salt and pepper, to taste. Puree in a food mill, return to the pan, and keep warm over simmering water. Use as needed.
Yield: about 2 1/2 cups
(Recipe courtesy Wolfgang Puck, Adventures in the Kitchen, Random House, 1991)