Let's get prepared ...
First, make the mayonnaise - two egg yolks, whisk until lighter and fluffy and then gradually add avocado oil (or extra virgin olive oil) in constantly whisking. You will get a feel for how much oil you need, but the exact ratio does not really matter.
Defrosted some frozen cooked prawns and once defrosed, combine into the mayonnaise and optionally add a spoon of creme fraiche.
Cut some thin lemon slices and cut mostly across the diameter so that a twist will be held by one side of the slice.
Put the lot into the fridge.
When ready to serve, take slices of smoked salmon, spoon a portion of the prawn mayonnaise onto the smoked salmon and roll up.
Garnish with a twist of freshly milled black pepper or some chopped dill and lay a lemon slice over the top.