Over a pan of simmering water, steam the crayfish tails for 5 minutes. The flesh should be succulent and opaque.

In a bowl, toss the red onion, lime juice, chilli, coriander and avocado oil and scatter over the crayfish and avocado halves. Season to taste and serve with the garlic aïoli.

To make the aïoli: In a blender, combine the egg, lemon juice, mustard, garlic and seasoning, to taste. With the motor still running, slowly add both oils in a thin, steady stream until the mixture is thick and creamy.