Step 1Toast the fennel and coriander seeds in a heavy skillet over medium-high heat until they are fragrant, stirring often, about 2 minutes. Cool. Use a heavy-bottom skillet on a hard surface to crush the seeds. Combine the seeds with the salt and pepper on a small plate. Dividing the spices equally, press them onto the tuna on all sides to make a firm thin crust. (The recipe can be made ahead to this point and refrigerated for several hours.)
Step 2When you are ready to serve, heat the oil in a small heavy skillet over medium-high heat until the oil is smoking. Sear the tuna about 1 minute on each side; the tuna will be barely rare and barely warm in the center. Alternatively, cook the fish to your taste, remembering that tuna cooked through tends to be dry and tasteless.
Step 3To serve the tuna, cut it into 1/4-inch thick slices. Arrange 2 Soybean Pancakes on each plate and top with tuna slices, then with the Basil, Olive and Soybean Garnish, dividing all evenly.