PreparationMake potato cakes: Preheat oven to 375°F. Bake potatoes until tester can pierce center but potatoes are not yet tender, about 30 minutes. Cool. Peel and coarsely grate potatoes. Transfer grated potatoes to bowl. Add chives. Season to taste with salt and pepper. Mix in egg white. Oil baking sheet. Press 1 heaping tablespoon potato mixture onto sheet, forming 2-inch round. Repeat with remaining mixture, forming 8 cakes total. Add enough oil to heavy large skillet to reach depth of 1 inch. Heat oil to 350°F. Add potato cakes to skillet and fry until golden, about 2 minutes. Drain on paper towels. (Can be made 1 day ahead. Cool; cover and chill. Rewarm in 350°F oven about 10 minutes before serving.) Make egg mixture: Gently mix all ingredients in small bowl. Make horseradish crème fraîche: Combine first 4 ingredients in medium bowl. Using electric mixer, beat until peaks form. Season with salt and pepper. Place 1 warm potato cake in center of plate. Place 2-inch-diameter cookie cutter or biscuit cutter with 1-inch-high sides around potato cake. Top cake with 2 tablespoons egg mixture; press to adhere. Press 2 tablespoons salmon atop. Dollop with 2 tablespoons horseradish crème fraîche. Gently remove cookie cutter. Smooth top. Top with small spoonful caviar. Repeat with remaining cakes. Drizzle basil oil around if using.
PreparationMake potato cakes: Preheat oven to 375°F. Bake potatoes until tester can pierce center but potatoes are not yet tender, about 30 minutes. Cool. Peel and coarsely grate potatoes. Transfer grated potatoes to bowl. Add chives. Season to taste with salt and pepper. Mix in egg white. Oil baking sheet. Press 1 heaping tablespoon potato mixture onto sheet, forming 2-inch round. Repeat with remaining mixture, forming 8 cakes total. Add enough oil to heavy large skillet to reach depth of 1 inch. Heat oil to 350°F. Add potato cakes to skillet and fry until golden, about 2 minutes. Drain on paper towels. (Can be made 1 day ahead. Cool; cover and chill. Rewarm in 350°F oven about 10 minutes before serving.) Make egg mixture: Gently mix all ingredients in small bowl. Make horseradish crème fraîche: Combine first 4 ingredients in medium bowl. Using electric mixer, beat until peaks form. Season with salt and pepper. Place 1 warm potato cake in center of plate. Place 2-inch-diameter cookie cutter or biscuit cutter with 1-inch-high sides around potato cake. Top cake with 2 tablespoons egg mixture; press to adhere. Press 2 tablespoons salmon atop. Dollop with 2 tablespoons horseradish crème fraîche. Gently remove cookie cutter. Smooth top. Top with small spoonful caviar. Repeat with remaining cakes. Drizzle basil oil around if using.