Preparation In a saucepan cover potatoes with salted cold water by 1 inch and simmer until just tender, 10 to 15 minutes. Drain potatoes in a colander and cool completely. Cut potatoes crosswise into 1/4-inch-thick slices. Rinse herring under cold water and pat dry with paper towels. Cut fillets diagonally into 1/2-inch-thick slices. Assemble canapés: Arrange a herring slice on each potato slice. Top each canapé with about 1/2 teaspoon sour cream. Top half of canapés with egg and half with beet. Sprinkle canapés with scallion.
Preparation In a saucepan cover potatoes with salted cold water by 1 inch and simmer until just tender, 10 to 15 minutes. Drain potatoes in a colander and cool completely. Cut potatoes crosswise into 1/4-inch-thick slices. Rinse herring under cold water and pat dry with paper towels. Cut fillets diagonally into 1/2-inch-thick slices. Assemble canapés: Arrange a herring slice on each potato slice. Top each canapé with about 1/2 teaspoon sour cream. Top half of canapés with egg and half with beet. Sprinkle canapés with scallion.