Cut the raw salmon into small cubes. Marinate the salmon by mixing in the sesame oil, vinegar and soy sauce. Then keep the salmon sealed in the fridge for 24 hours.
Grate the lemon and squeeze the juice. Cut the avocado into small cubes (same size as salmon cubes). Mix the salmon and avocado together and add 1 tbsp lemon zest and 1 tsp of lemon juice in a bowl.
Add the fresh chives and mayonnaise. Stir well and season with black pepper. Put the mixture into a ring on a nice plate and press the top. Repeat this until you have four salmon tartlets.
Garnish your dish with cress. Enjoy!