To make Pickled Plum-Soy Glaze: In saucepan, combine soy sauce, mirin, plum wine, sake, brown sugar and bonito flakes. Bring to a simmer. Mix together cornstarch and water. Slowly add to simmering soy mixture, whisking constantly until glaze thickens. Strain; whisk in plums. (Yield: about 3 cups)
For each serving, to order: In sauté pan, brown 1 Sesame Rice Cake (recipe below) in canola oil until light golden and crisp on both sides. Sear 1 tuna block in sesame oil until brown on all sides and medium rare. Cut crosswise into 1/2-inch slices. Place rice cake in center of plate; fan tuna slices on one side of cake. Spread 1 tablespoon Wasabi Butter on tuna; broil about 30 seconds or until butter melts. Drizzle 2 tablespoons Pickled Plum-Soy Glaze on and around tuna; garnish with 1 shiitake cap, 1/4 cup cilantro and 1 tablespoon green onions.
Sesame Rice Cakes: In rice cooker, cook 3 cups short-grain rice. Stir in 1/4 cup mirin, 1/4 cup rice vinegar, 4 ounces minced green onions and 3 tablespoons toasted sesame seed. Spread rice mixture on half-sheet pan in thin, even layer. Place a sheet of parchment paper or plastic wrap on top; press down lightly on surface of rice with another half-sheet pan to even rice layer and compact slightly. Refrigerate until cold. Remove paper or plastic; cut into 24 (3 x 3-inch) squares. (Yield: 24 rice cakes)
Recipe by Chefs Debbie Gold and Michael Smith, 40 Sardines (Overland Park, KS)