Cut the salmon, previously frozen for at least 48 hours, into cubes. Put the fish in a bowl and add a dash of lime, salt and sprinkle some olive oil. Mix well.
On the other hand, dice the avocado, add a pinch of salt and pepper and mix well.
Assemble the tartar: on the base, the avocado, and the salmon on top. Crown with a decent amount of Codium Seaweed Spheres.
Sprinkle a pinch of black sesame over it.