We were fortunate enough to receive more fresh oysters in our recent share, but we didn't want to just fry them up. I asked a fellow foodie for suggestions and he recommended a cold miso soup. We happened to have most of the ingredients on hand, and it sounded like the perfect light, summer dinner.
We started by making a dashi, following Alton Brown's recipe. It's essentially the Japanese equivalent of a broth, imparting the flavor of seaweed and bonito flakes in water, the same way you would a chicken or beef stock. Though we didn't have any kombu on hand, we did have nori, so we used that instead. They're fairly similar dried seaweeds, and it proved to be a decent substitute.
Start by soaking your seaweed in water for about 30 minutes. Then heat the pan so the water comes to a slow simmer, and let it cook for another 10 minutes. This will help flavor the water. Remove your seaweed, increase the heat, and let the water boil for another 5 minutes. Reduce the heat again, and add your katsuobushi, or bonito flakes. Let the bonito flakes simmer for about 10 minutes. I love the smoky, umami smell of the flakes on their own. Once the bonito flakes have simmered, strain the liquid through a fine mesh strainer or cheesecloth, and your dashi is ready! You can reserve the bonito flakes for another use.
Now you're ready to make your soup. We found another Alton Brown recipe for miso soup, with a few additions. With the dashi we just made, we heated it in a pot and brought it to a low simmer. While the dashi warmed up, we pressed our tofu, to get the liquid out of it. We just sandwiched it between paper towels and plates, with a weight on top.