Memil Kalguksu: Korean Buckwheat Handmade Noodles in Chilled Broth

In a large mixing bowl, whisk the buckwheat flour, all-purpose flour, and salt together. Add the cold water gradually, stirring with a wooden spoon until a shaggy dough forms. Knead by hand for 5 to 6 minutes until the dough is smooth and elastic but still slightly tacky. If it feels too dry, add water 1 teaspoon at a time; if too sticky, dust with a little all-purpose flour.

Wrap the dough tightly in plastic wrap or cover with a damp cloth and let it rest at room temperature for 30 minutes. This relaxes the gluten and makes the dough easier to roll thin without tearing.

On a lightly floured surface, roll the dough out into a thin rectangle, about 2 mm thick. Flour the surface lightly as needed to prevent sticking. Fold the dough into thirds and cut into thin strips about 3 mm wide. Toss the noodles with a little flour to keep them separated.

Bring a large pot of salted water to a rolling boil. Add the noodles and cook for 3 to 4 minutes, until they float and are just tender but still chewy. Drain and rinse immediately under cold running water to stop the cooking and remove excess starch. Drain well.

In a blender, combine the toasted sesame seeds, soy milk, cold water, soy sauce, sesame oil, garlic, and sugar. Blend on high for 1 to 2 minutes until completely smooth and creamy. If you prefer a thinner broth, add a splash more water. Taste and adjust seasoning.

Divide the chilled noodles between two deep bowls. Pour the sesame broth over the noodles. Top with julienned cucumber, half an egg per bowl if using, and a sprinkle of toasted sesame seeds. Serve immediately with extra broth on the side if desired.