This is a dish that has evolved and matured over time. If you do not have the time to make onion juice, saba or aged balsamic work as great alternatives. However, the onion syrup itself is a great staple to have in the kitchen and one of my favorite sauces for steak.
12 ounces center cut sashimi grade Blue fin Tuna Loin
1/2 cup of fresh mint leaves
1/2 cup of olive oil
1/2 cup micro sorrel leaves
4 ounces Comte cheese
3 white onions juiced
2 tablespoons of soy sauce
2 tablespoons of sherry vinegar
Fleur de Sel
Freshly Ground Black Pepper
Cut the tuna loin into four equal portions and place into a dish, which will hold the fish. Blanch the mint in boiling salted water and then shock it in ice water. Drain the mint and puree it with the olive oil. Strain the mint oil and pour it over the fish in its dish. Turn the fish in the oil so that it is evenly coated. Cover the fish with plastic and place in the refrigerator. Turn the fish every hour so the mint oil infuses the fish completely.
Juice and strain three white onions. Mix the juice with the soy sauce and sherry vinegar. Reduce the juice till it becomes thick and syrupy. Remove from the heat and let cool. Slice the Comte cheese into thin sheets and then cut into ¼ inch squares. Remove the tuna from the oil and pat it dry. Place each piece of tuna on a plate and season with fleur de sel. Place the sorrel leaves and Comte squares over the fish in a polka dot like pattern. Spoon the onion syrup in a small pool to the side of the tuna so that the diner can dip the tuna into the syrup.