Cut the two large slices of tofu in half, so you have 4 pieces. Cut the nori into the forms of the tofu and put the nori sheet on the tofu slices. Press the nori a bit onto the tofu so that it sticks.
Combine all-purpose flour and 1/4 teaspoon salt on a deep plate. Coat all the tofu filets in the flour and set them aside. Then add corn starch, 1/4 teaspoon salt, and turmeric to the rest of the flour on the plate. Add more flour if there isn't much left. Add seltzer water and whisk until it's a slightly thick, runny batter.