1quart oysters shucked selects, save the liquor (see notes)
2scallionswhite and light-green parts, chopped (1/2 cup)
Combine the water, dashi powder, fish sauce, ginger, oyster sauce, gochujang, kimchi and mushrooms in a large Dutch oven over medium-high heat.
Bring to a boil, stirring occasionally, then reduce the heat to medium, cover and cook for 20 minutes, stirring occasionally, to let the flavors meld. (At this point, the soup can be cooled, covered and refrigerated for 1 or 2 days.)
Stir in the spinach and oysters; cook uncovered for about 4 minutes, til the edges of the oysters begin to curl.
Ladle into individual bowls. Garnish with the chopped scallions; serve immediately.
Different brands of kimchi, the traditional Korean condiment made with fermented cabbage, usually have different vegetables added to them. The brand used in this recipe includes carrots and peppers, which give the flavor of this easy soup added dimension. When choosing a kimchi, opt for one that is not too sour, so the oysters will not be overpowered. Taste the kimchi to assess its spiciness, and adjust the seasoning for this dish accordingly."Select" oysters are what you'll usually find in the seafood department of grocery stores; the term refers to their size.Make Ahead: If you plan to make this soup in advance, refrigerate it without the oysters or spinach. Once the soup is reheated, they can be added just before serving.