Preparation / Directions:
PREHEAT OVEN TO 450F
Heavily butter 4 pieces of 9-by-12-inch aluminum foil, then sprinkle with salt and white pepper.
Shred the potatoes and mix with lemon juice and scallions. Make a bed using half the potatoes on each piece of aluminum foil. Place a salmon fillet on the potato bed, sprinkle with salt and pepper and cover with remaining potatoes. Press down on the potatoes, then enclose tightly in foil.
Place in oven for 15 minutes. Meanwhile, combine shallots, wine and vinegar in a saucepan. Place over medium heat and cook until most of the liquid is evaporated.
Remove from the heat and beat in remaining butter. Add salt and white pepper to taste and set briefly aside in a warm place. When it's time to put dinner on the table, heat the broiler. Unwrap the salmon, and place it close to the heat.
Brown well, about 2 minutes per side.
Arrange the salmon on a platter and serve the sauce separately