Russian
Boil the unpeeled beets until tender, 50-60 minutes, and in a separate pot boil the unpeeled potatoes and carrots for 20-25 minutes. Cool completely and peel.
Remove any bones from the herring and cut it into 1 cm pieces. Finely chop the onion.
Coarsely grate the potatoes, carrots and beets into separate bowls.
Spread the herring in an even layer in a 22 cm dish or ring mold, scatter the onion over it and spread with a thin layer of mayonnaise.
Cover with the potatoes and spread a thin layer of mayonnaise on top, then add the carrots and another thin layer of mayonnaise.
Finish with the beets and cover the top with the remaining mayonnaise.
Refrigerate for at least 180 minutes so the layers set, then cut into portions.