Boil beets first, cool, peel. Cut the onion into strips, pour boiling water for 2 minutes, drain the water, squeeze. Put a layer of herring diced on a dish, apply a net of mayonnaise. Put a layer of onions, apply a mesh of mayonnaise. Put a layer of diced cucumbers, apply a mesh of mayonnaise. Grate beets on a coarse grater, lay out evenly, apply a grid of mayonnaise. Garnish the salad, leave for 30 minutes in the refrigerator and serve.