Put the Ikura in a blender jug with the Yuzu juice, blend, and emulsify with the olive oil and then keep refrigerated.
For the Ponzu:
Put the soy sauce, dashi-no-moto, mirin and kombu in a saucepan to boil and as soon as it reaches the boil remove the kombu and allow the liquid to cool. When completely cold, add the Yuzu juice and mix well.
Cut the salmon into thin strips of 3 mm thick and arrange on a plate. Spoon the mayonnaise on top and decorate with some Ikura eggs. Place some puffs of fried tempura on the side.
Drizzle a little Ponzu sauce at the bottom of the plate.