Add into a bowl the avocado layer ingredients and drop in the avocado. Mix gently and keep aside.
Pat dry the tuna and with a sharp knife cut in 1cm cubes.
In the meantime, add in another bowl the tuna ingredients except of the tuna, sesame seeds and lime zest. Mix well and drop in the tuna cubes. Mix gently and allow to marinate refrigerated for no more than 20’.
Assemble the tartare by adding in a tall round cookie cutter the avocado layer and press well. Add on top the tuna and press gently. Remove the cookie cutter and garnish with the sesame seeds and lime zest. Repeat for the rest of the quantities left, in my case it was 4 all together.