The beauty of soba noodle soup is that all you have to cook are the soba noodles and a strongly flavored broth. Then you can top it with almost anything you like. I like to make a big batch of dashi, the Japanese broth made by simmering just two ingredients: the thick seaweed kombu and then bonito flakes. I freeze some of it for miso soup, and then flavor the rest in the traditional style for noodle soups, aka kakejiru, with soy sauce and mirin, plus a little salt and sugar.
You can stretch two meals out of the noodles and broth, eating them topped with roasted chicken thighs, scallions, and shichimi togarshi for one dinner, and then using the leftover noodles and broth for lunch the next day. For a quick workweek lunch, I like to add flaked hot-smoked salmon, which you can pick up in the refrigerated seafood section of most grocery stores, plus a bunch of refreshing vegetables: grated daikon, peppery watercress, thinly sliced cucumber, and a showering of sharp scallion. —Mari Uyehara
For the soup:
dashi (see recipe below)
hon mirin (preferably one made with real sake, like Takara)
dried soba noodles
scallions, thinly sliced on the bias, whites and light greens only
cucumber, thinly sliced
(4 oz) packages of smoked salmon chunks, broken into bite-sized pieces
To make noodle broth (kakejiru): Add the dashi, salt, soy sauce, sugar, mirin, plus 1/2 cup cold water to a pot over medium-high heat and bring to a boil. Remove from heat.
To make soba: Boil noodles according to package directions. Drain in fine-mesh strainer and rinse well under cold water. Shake them dry.
To serve: Divide noodles among four bowls. Add broth. Top each bowl with vegetables, salmon, shichimi togarashi, and bonito flakes.
To pack for lunch: Divide vegetables, salmon, and noodles between four large mason jars or containers. Starting with the scallions, then watercress, cucumber, daikon, and salmon, stack them in the jar or container. Add the cooked soba noodles last. Twist a lid on securely, turn upside down and store in refrigerator, so that the toppings sit on top. Divide the noodle broth between four more containers, so the broth and noodles are packed separately. When you're ready to eat, gently reheat the noodle broth. Carefully open the upside-down mason jar or container into a bowl so that the noodles fall in first and the rest of the ingredients sit on top. Pour broth into the bowl. Garnish with shichimi togarashi and bonito flakes.
For the dashi:
Rinse konbu under cold water and place it in a medium pot with 2 quarts cold water. Heat over medium-high heat until tiny bubbles form at the edges, about 12-14 minutes. Don’t let the water come to a full boil, which will bring out bitter flavors. If you can puncture the kombu easily, it is ready; remove it with tongs. If it is still stiff, leave it in the pot, add about ¼ cup more water and cook for another few minutes.
After removing the konbu, add 1/2 cup cold water and bonito flakes. Bring just to a boil, about 2 minutes, and then remove from the heat and cover. Don’t let the dashi boil too long or the bonito flavor will be quite strong. Let it sit until the bonito flakes settle at the bottom of the pot, about 10 minutes. Strain through a fine-mesh sieve or cheesecloth into another pot. Do not press the bonito flakes. The used konbu and bonito flakes can be refrigerated or frozen and used one more time to make a second dashi. The dashi will keep in the refrigerator for a few days and in the freezer indefinitely.
Mari Uyehara is a lifestyle writer based in Brooklyn and Massachusetts. She was previously a senior editor at Saveur, the food & drink editor of Time Out New York, and the food editor of Martha Stewart Living Radio. Follow her on Twitter and Instagram.