Yachae Kalguksu is a Korean vegetable soup with the addition of knife cut noodles. There are many variations of the broth for Kalguksu and it is most often enjoyed during the summer. This particular recipe includes vegetable stock, onion, scallions, garlic, ginger, potato, and zucchini. Evan is a soup lover like me and this was a hit for both of us. He also had fun making the noodles (though a couple may have been lost in his exuberance of separating the strands).
The star of this dish, the knife cut noodles, are made by a simple flour and water dough. After a short rest period, the dough is rolled out, folded up, and hand cut into thin ribbons. The trick here is to flour everything and use a very sharp knife. Without enough flour, the noodles won’t separate. I cut the noodles quickly to avoid pinching the dough together.
You can either add the raw noodles straight to the broth or cook separately. For the photos, I boiled them separately to make the broth clearer. Usually, I just add them straight to the soup to save time and dishes.
The amount of salt needed may differ depending on the salt content of the vegetable stock and individual taste.
Gochugaru is a hot Korean red chili powder. The best gochugaru is made from red chili peppers that have been dried in the sunlight. You can make your own (not common anymore) and it is also available on Amazon as fine or coarse powders: Singsong Korean Hot Pepper Fine Type Powder and Singsong Korean Hot Pepper Coarse Type Powder. I have not been able to find it at any grocery stores in my area, but I have seen it in the local Asian food markets. If you must, cayenne powder can be substituted, but the flavor is just not as authentic as the hot and sweet, smokey gochugaru.
Yachae Kalguksu (Korean Knife Noodle and Vegetable Soup)
Adapted from Emily Ho- The Kitchn
1 1/2 cup all purpose flour
1/2 teaspoon salt
1 teaspoon vegetable oil
1/2 cup cold water
2 quarts vegetable stock
1/2 onion, thinly sliced
2 scallions, thinly sliced
6 cloves garlic, peeled and roughly chopped
2 inch piece ginger, peeled and thickly sliced
1/2 teaspoon salt
1 medium potato (white or yukon gold), peeled, thinly sliced, and cut into half circles
1 medium (Korean if possible) zucchini, thinly sliced and cut into half circles
1-2 scallions (green only), thinly sliced
1 teaspoon toasted sesame seeds, ground coarsely
1/4 teaspoon gochugaru (Korean red pepper powder), to taste
To make the noodles: In the bowl of a large food processor fitted with a dough blade or a large bowl, mix together flour and salt. Pulse in (or work in by hand) the oil, then the water until a soft dough comes together.
On a lightly floured surface, knead the dough until smooth and elastic. Wrap in plastic or cover for at least 30 minutes to allow to rest.
While the dough is resting: In a large pot, bring vegetable stock to a boil. Gently add the sliced onions, scallions, garlic, ginger, salt, and potato. Cover and reduce heat to medium low. Allow to simmer until potatoes are tender and soup is flavorful, about 30 minutes. Add salt if needed.
Place rested dough on a well floured surface. Roll out the dough, adding more flour as needed to prevent sticking, until about a 1/16-1/8th inch (2 millimeters) thick rectangle. Make sure both sides are coated with flour and fold up about 4 times starting from the longest side. Use a very sharp, floured knife to quickly cut the noodles into 1/4 inch wide strips. Toss immediately to separate.
Add the zucchini to the simmering soup. Continue to cook until tender.
Either add the noodles to the soup or cook in a separate pot of boiling water until just tender, drain, and add to the soup.
Serve immediately with scallions, sesame seeds, and gochugaru.