To make the dressing, combine the sherry vinegar, olive oil, sesame oil, lemon juice, and sesame seeds into a jar, shake well, and place aside.
To make the Guinness soaked tuna, first combine the sugar, salt, and Guinness to make a brine. Stir well, until the sugar and salt are dissolved. Add the tuna and brine for 12 hours in the refrigerator. Remove tuna, wash under cold water, and dry with a clean towel. Slice 4-inch long and 1/4-inch thick ribbons off the tuna and wrap 1 around each of the scallops and oysters. Gently sear the oysters and scallops in a very hot fry pan, until the tuna cooks on the outside and the scallops and oysters just lose their translucence. Then remove from heat.
Place 3 scallops on a plate. Toss the oysters with salad greens and 2 teaspoons of the dressing, and place in between the scallops. Drizzle extra dressing around the plate and serve.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Terry White, Four Seasons Hotel - Dublin