Kitsune Udon is an iconic Japanese noodle soup featuring seasoned fried tofu in dashi broth and topped with pink-swirl narutomaki fish cake and scallions. This hearty udon soup is one of the most popular, classic Japanese noodle dishes.
Gather all the ingredients.It's really important to have good flavorful dashi for this recipe. Although you can take a shortcut by using dashi powder or a dashi packet, I encourage you to make dashi from scratch because the broth tastes so much better! It only takes less than 30 minutes to make. For vegetarian/vegan, please use Kombu Dashi (instructions below).
To Make the Homemade Dashi
Put the kombu and water in a measuring cup for at least 30 minutes. If you have time, soak for 3 hours or up to half a day. The kombu’s flavor comes out naturally from soaking it in water. If you don’t have time, skip soaking.
Transfer the kombu and water to a saucepan. Slowly bring to a boil over medium-low heat.
Just before the liquid boils (you will see bubbles around the edges of the pan), remove the kombu. If you leave the kombu inside, the dashi will become slimy and bitter. Now, this broth is vegetarian/vegan-friendly Kombu Dashi and it's ready to use. For non-vegetarian/vegan, add the katsuobushi and bring it to a boil again.
Once the dashi is boiling, reduce the heat, simmer for just 15 seconds, and turn off the heat. Let the katsuobushi sink to the bottom, about 10-15 minutes. Strain the dashi through a fine-mesh sieve set over a saucepan. Now you have homemade Awase Dashi.
To Make the Soup Broth
In a saucepan, add the dashi, mirin, sugar, soy sauce, and salt and bring it to a boil. Once boiling, turn off the heat or cover and keep on a low simmer.
To Prepare the Toppings
Squeeze the excess liquid from the Inari age (or you can keep it as is). Cut the green onion into thin slices. Cut the narutomaki fish cake into ⅛-inch (3 mm) slices.
To Cook the Udon Noodles
Bring a large pot of water to a boil for the udon noodles. My favorite udon is frozen Sanuki udon. Reheat the frozen udon noodles in boiling water for 1 minute (no need to defrost). If you use dry noodles, follow the package instructions.
Pick up the noodles in a strainer or drain the hot water. Make sure to shake off the excess water (which will end up diluting your soup).
Divide the drained udon noodles into individual serving bowls. Pour the hot broth over the noodles to cover. Top with the Inari age, narutomaki, and green onions. Sprinkle the shichimi togarashi on top (optional).