"Herring under a Fur Coat" - Russian herring salad

This layered salad is pronounces in Russian as "selyòdka pad shoùbay" and that really means "Herring under a Fur coat". They also abbreviate it to "Shoùba", e.i. "Fur coat". 
Shoùba is a winter salad and especially used for a New Year celebration, it is quite beautiful and has a rich taste. They also say it's necessarily accompanied by a Vodka shot.
 
INGREDIENTS:
Servings: 4

1 smoked/salted herring
2-3 potatoes
2-3 carrots
1 big beetroot
2 eggs
1/2 onion
225ml mayonnaise   

1. Boil potatoes and carrots in their jackets, when they are ready cool them down and peel.
2. Boil beetroots the same way.
3. Boil eggs and cool them down.

4. If you take a whole herring then you need to peel it and take away all the bones. And if you have a herring fillet then just cut it into tiny pieces.
5. Cut all the other ingredients in small pieces and keep them each in a separate bowl.  
Note: Some other variations of this recipe advise to grate the ingredients, though in the original version the ingredients are chopped into tiny cubes.
6. Chop onion finely and if don't like it's strong taste, soak it in boiling water for couple of minutes and squeeze it. Some people don't like onion taste in this salad, if you are one of those, then don't put it!
7. Let's start forming our salad, you need to spread every ingredient as a layer in this sequence:

- herring. 
- onion
- mayonnaise
- potatoes
- mayonnaise
- carrots
- eggs
- mayonnaise
- beetroots
- mayonnaise (a bit more)

You need to slightly salt each layer.

8. Press the top of the salad with the wet hands to create a kind of  dome. 

9. Refrigerate the salad for some hours in order for it to get soaked well into mayonnaise and get chilled well to cut it easily and show nicely the layers.

10. You may decorate the salad right before serving with either some grated egg yolk or some chopped parsley and dill. Serve as a slice of a cake.

Note: I prepared the original version and original layout of this salad but we are modern people and I suggest to try to compose the salad in small ring-form as a single portion, this way the layers will be presented really nicely. 
Note: For those who don't have such a kitchen tool, you may cut a big plastic bottle into a 10cm high ring.