Wherever you stand on the cold soup spectrum—do you think they’re silly and have no reason to exist? Or do you just think we ought to call them smoothies, rather than soup? Didn’t we discuss this last year?—today’s recipe is one I was excited about well before I found time to make it. I wanted a simple edamame soup that would provide a good base for some fun garnishes. It turned out to be rich and hearty whether you serve it hot or cold, and easy and cheap, too.
Dashi, or kombu broth, is one of my happiest discoveries in the kitchen over the past few years. It’s one of the foundations of Japanese cuisine, and traditionally it contains both kombu—a sea vegetable—and bonito flakes—which are grated, dried fish. I’ve had success making dashi vegetarian by simply omitting the bonito, as I do in this recipe. It’s also much easier to make than vegetable stock, requiring no chopping, straining, or (most importantly during this permanent heat wave of a summer) application of heat.
The soup itself is perfectly good hot, as I said, but I like it a lot as a cold soup because of the garnishes. I’ve listed out several below, but my favorites are the apple, ginger (used sparingly), scallions, cucumber, and yogurt. These ones offer the crisp qualities that satisfy on a hot day. The nori is quite subtle, and slightly emphasizes the flavor of the kombu broth (this isn’t a bad thing at all). If you use the radish, go easy on it—a little bit goes a long way. You might have some ideas for garnish, too, and I hope you’ll share them.
Cold Edamame Soup
Serves 4 to 6
1 quart (4 cups) vegetarian dashi* (see below)
2 tablespoons neutral oil
4 scallions, white and green parts, sliced thinly
2 shallots, minced
1 tablespoon grated ginger
2 twelve-ounce packages frozen, shelled edamame
1 teaspoon kosher salt
4 teaspoons brown rice vinegar
2 teaspoons mirin
1/4 cup roughly chopped mint
Garnishes: Apple cut into thin matchsticks, freshly grated ginger, grated diakon radish, nori sliced into thin strips, plain yogurt or a swirl of coconut milk, thinly sliced scallions, cucumber cut into matchsticks, mint leaves julienned or whole, whole edamame beans
1. Heat the oil in a soup pot or Dutch oven over medium-low heat. Add the scallions and shallot and cook until just softened, about 2 minutes, then add the ginger. Stir for a minute, then pour in the kombu broth. When warm and just simmering—do not bring the kombu to a full boil or you’ll compromise the flavor—add the edamame and the salt. Cook for 5 to 7 minutes, until tender. Let cool. To expedite cooling, prepare an ice bath in a large bowl, then transfer the soup mixture to a bowl that fits inside the ice bath. Submerge, watching the water levels carefully so that you don’t end up letting ice water into the soup, and stir until cooled. Alternatively, just refrigerate the mixture for 4 hours or overnight.
2. Transfer to a blender. Add the vinegar, mirin, and mint, and puree until smooth. Taste for flavor, adding more vinegar, salt, or mint as needed. This soup is best served really cold, so you may want to let this mixture chill again before serving. And while you’re at it, chill a few soup bowls, too.
3. To serve, divide the soup among the (cold) bowls, and garnish as you please. See notes above for my favorite garnishes, but feel free to experiment.
* Dashi: To make a quart of dashi, combine a 4-by-4 inch piece of kombu and 4 cups water. Cover and let stand at room temperature for 4 hours, or store in the refrigerator overnight. Strain out the kelp—you can eat it if you’d like—and you’re good to go. The flavor varies a lot depending on what kind of kombu you buy, so as you continue to incorporate dashi into your diet, fiddle with the steeping times and water-to-kombu ratio until you get the flavor as you like it.