Salmon Tatar on Potato Mash with Apple-Horseradish sauce

Made with Canadian wild salmon -Sachimi quality    -  a feast for the eyes, but horror at the check out counter!

This is a recipe from Austrian Chef Elisabeth Grabmer. But I changed a few things.
She used fresh char. That is not available here to eat raw. She used some high end kitchen gadget to juice 40 g of cucumber, a bit of apple and 10 g of chives. I just chopped it.

The base of the tatar is a smoth potato mash. I made some last night and stored the rest in the fridge.
I am lucky that I had that part of the recipe already done, otherwise the prep time would have gone on for ever. The 4 components of the dish take some time.

recipe for 3:
220 g salmon -sachimi quality
1 shallot
bunch of chives
12 cm cucumber
1 red apple
2 tbsp horseradish
1 Lime
1 tsp olive oil
pinch of sugar

mash:
200 g floury potatoes
salt
macis ground
nutmeg grated
milk
butter
 

vinaigrette: 
30 ml chicken stock
20 ml  cider vinegar
Piment d`Espelette
spritz lime juice
some zest
chopped cucumber
chopped chives
salt and pepper
50 ml rapeseed oil 

Prepare the mash first. It can only be used as the base for the tatar when it is just luke warm. Otherwise it will cook the fish.

Take the skin off the salmon and finely cut it with a sharp knife.
Peel the cucumber piece and cut it into quarters. Take the seeds out completely. Cut it into match sticks and then into tiny cubes. Half of them to the salmon, the other in a bowl as a part of the vinaigrette.
Cut the chives very fine and do split it too between both bowls.
Peel and chop the shallot, put it in a fine sieve and place it in a bowl and pour boiling water over it. Let it sit 30 seconds, then drain and cool down. Add to the salmon.
Grate halve of the zest of the lime into the salmon bowl, the other in the vinaigrette bowl.

Finish the tatar with a pinch of sugar, salt and pepper and olive oil. Let it rest for a while.

Make the apple-horseradish cream:
grate the apple on a box grater, add lime juice and horseradish and salt and pepper.

Finish the vinaigrette with cider vinegar, a dash of lime juice, Piment d´Espelette, salt and pepper and rapeseed oil.

Use 3 serving rings on 3 plates and start with the potato mash.
Add the salmon tatar.
Put a dollop of apple-horseradish on top.
Get the ring off.
Drizzle with vinaigrette.