This Japanese udon noodle soup with kimchi-miso broth is made with mushrooms and tofu. Top with roasted, peeled tomato halves, if desired.
Bring a large pot of lightly salted water to a boil. Cook udon in boiling water, stirring occasionally, until noodles are tender yet firm to the bite, 10 to 12 minutes. Drain and rinse under cold water to stop the cooking; set aside.
Combine water and kombu in a large soup pot over medium heat; bring to a gentle simmer. Turn off heat and pour through a fine sieve or strainer. Pour broth back into the soup pot and discard the kombu. Add mushrooms, kimchi, bell pepper, green onions, miso, soy sauce, rice vinegar, mirin, maple syrup, ginger, sesame oil, garlic, lime juice, salt, and pepper. Bring to a simmer and cook for 15 minutes. Turn off heat and adjust seasoning, if necessary.
While soup is cooking, heat oil in a large skillet over medium-high heat. Add tofu cubes and fry on each side until browned, 1 to 2 minutes per side. Remove tofu to a paper towel-lined plate to drain. Add tofu to the soup.
Divide udon noodles amongst 4 bowls. Ladle the hot broth-tofu mixture over top and serve immediately.
Per Serving: 572 calories; protein 16.1g; carbohydrates 89.4g; fat 15.2g; sodium 2018.5mg.