Japanese Nabeyaki Udon Soup
6 cups prepared dashi stock
1/4 pound chicken, cut into chunks
2 carrots, diced
1/3 cup soy sauce
3 tablespoons mirin
1/2 teaspoon white sugar
1/3 teaspoon salt
2 (12 ounce) packages firm tofu, cubed
1/3 pound shiitake mushrooms, sliced
5 ribs and leaves of bok choy, chopped
1 (9 ounce) package fresh udon noodles
2 leeks, diced
Heat dashi stock, chicken, carrots, soy sauce, mirin, sugar, and salt in a pot over medium heat. Simmer until chicken is no longer pink in the center, 5 to 7 minutes. Add tofu, mushrooms, and bok choy, stirring until vegetables are tender, about 5 minutes more.
Stir udon noodles into broth and simmer until tender, 3 to 4 minutes. Add leeks and crack eggs into soup; simmer until eggs are slightly firm, about 5 minutes more.