Peel and boil the Charlotte potatoes until tender. Mash with a fork, season with pepper, salt, and Tahiti vanilla salt. Set aside.
Cut the fresh bluefin tuna fillet into 4 thick 160g steaks (reserve scraps for other uses).
Prepare the balsamic caramel: Reduce the balsamic vinegar. Make a caramel, deglaze with soy sauce, then add veal jus. Finish by incorporating the prepared caramel.
Finely chop the chervil. Dice the yellow lemon into a fine brunoise, blanch, drain, then candied by sweating in a little oil and sugar.
Sear the tuna steaks in very hot sunflower oil on both sides. Finish cooking 'au bleu' (rare) in the oven. Drain on absorbent paper.
To plate: Using a 10cm ring mold in the center of the plate, spread the mashed potatoes 1cm thick. Sprinkle paprika, chervil, and candied lemon on one end of the circle. Reduce the balsamic caramel to a thick syrup, whisk in a touch of butter off the heat. Glaze the top of each tuna steak in the pan for a lacquered finish. Drizzle the plate with the remaining reduction, avoiding the potatoes, and position the glazed steak atop the mash.
A signature creation by Chef Hubert
