Cup of Yum
1. Gather all the ingredients. [Optional] For the best flavor, soak the kombu in the water overnight (to make cold brew kombu dashi). If you don’t have time, start soaking the kombu as soon as you can. When you're ready to prepare this dish, start bringing a big pot of water to a boil for the soba noodles.

To Make the Homemade Soup Broth

Cup of Yum
1. Add 1 piece kombu (dried kelp) and 3 cups water (or the cold-brew dashi with the kombu) to a medium saucepan. Slowly bring it to a boil over medium-low heat (so the kombu dashi will be more flavorful). When it comes close to boiling, remove the kombu. You can make furikake rice seasoning with the spent kombu.
2. Add 1 cup katsuobushi (dried bonito flakes) and simmer for 30 seconds. Turn off the heat and let the katsuobushi sink to the bottom of the saucepan. Let it steep for about 10 minutes. Meanwhile, prepare the toppings.
3. Drain and reserve the dashi in a measuring cup (or bowl). Discard the katsuobushi or use it to make furikake rice seasoning with the spent katsuobushi. Put the dashi back into the saucepan.
4. Add 1 Tbsp sake, 2 Tbsp mirin, 2 Tbsp usukuchi (light-colored) soy sauce (or regular soy sauce), and ¼ tsp Diamond Crystal kosher salt.
5. Bring it to a simmer. Once boiling, remove from the heat, cover, and set aside.

To Prepare the Toppings

1. Rehydrate 2 Tbsp dried wakame seaweed in 1 cup water. Then, squeeze the water out and set aside.
2. Thinly slice 1 green onion/scallion.
3. Slide a knife under the kamaboko to detach it from the wooden board. Thinly cut 4 slices kamaboko (fish cake).

To Cook the Soba Noodles

1. In a pot of boiling water, cook 7 oz dried soba noodles (buckwheat noodles) according to the package instructions. You do not need to salt the water.
2. Drain the soba noodles and rinse them under cold water to get rid of the starch. Transfer the noodles to individual bowls.

To Serve

1. Pour the hot soup broth over soba noodles. Top with kamaboko, wakame seaweed, and green onions. Sprinkle shichimi togarashi (Japanese seven spice), if you‘d like. Enjoy while it’s hot.

To Make the Quick Soba Broth (with concentrated mentsuyu; optional)

1. Follow your mentsuyu bottle instructions to make the broth.
2. In a medium saucepan, combine 2⅓ cups water, ⅓ cup mentsuyu (concentrated noodle soup base), and 1 Tbsp mirin. Mix well. Bring it to a gentle simmer over medium heat. Cover with a lid and turn off the heat. The soba broth is ready to use.