Shrimps with blood orange mayonnaise & fennel

For ➍
1 large fennel
1 ts sea salt
36 medium shrimps (about 500 g)
2 blood oranges
5 cl rapeseed oil
seeds from ½ vanilla pod
mayonnaise:*
2 egg yolks
1 ts mustard
15 cl rapeseed oil
1 blood orange with bright red flesh
salt & lemon juice

Make the mayonnaise: put the egg yolks and mustard in a bowl and mix well with a mixer. Keep mixing and add rapeseed oil, drops first, then radiating the until the mayonnaise has thickened.
Grate the zest of ½ orange and squeeze the juice of the whole orange. Stir both in the mayonnaise. Season with salt and lemon juice.
Cut the fennel into quarters and cut each quarter into slices of 1 mm. Put them in a bowl and mix with the salt. Let stand 30 m.
Peel the blood oranges to the flesh. Cut the segments from between the membranes. Chop the slices into cubes.
Mix the vanilla seeds with the rapeseed oil. Rinse the fennel with cold water and drain. Pat dry and season with vanilla oil.
Grill or poach the prawns.**

Serve with the mayonnaise. Add the orange cubes to the fennel salad and a few tufts of green fennel.

*Or mayonnaise and add some juice.
**Or bake them, 1 -2 m each side. Or poach in microwave.