Thinly slice the tuna and arrange in a shallow dish. Pour the lemon juice and orange juice over it and let marinate at room temperature for 1 hour.
Place shallots in a small bowl and whisk in lemon juice and olive oil. Season with salt and pepper.
Season arugula with salt and pepper. Mound salad on a platter and arrange the slices of tuna around it. Lightly season both the salad and the tuna with sea salt and add a splash of vin cotto. Mangia.
Recipe courtesy of Chef Sal Passalacqua, Dimaio Cucina