Place the garlic, onion, ginger root, shiitake mushrooms and water in a large pot.
Bring to a boil and then cook over medium heat for 30 minutes. If you can't wait, cook the soup just 15 minutes. You can alsor cook it longer (1 hour or even longer), it will have a more intense flavor. Add more or less water if you change the cook time.
Strain the broth, set aside the mushrooms for serving and discard the veggies.
Pour the broth into the pot again, add the tamari or soy sauce and miso paste. Stir until well combined.
Prepare the noodles while the broth is cooking. Just cook them according to package directions. We added 1 tablespoon baking soda to the water, but it's optional. Drain and set aside.
Slice the tofu and cook it in a skillet over high heat until is golden brown for both sides. We didn't add any oil.
To serve, divide the noodles between four serving bowls, then top with the broth and add your favorite toppings. We added tofu, red cabbage, chives and soybean sprouts.
Keep the broth in a sealed container in the fridge for up to 5 days. Noodles and tofu can be stored separately in the fridge for 4 to 5 days. The rest of the toppings are better fresh.