Heat neutral oil over medium-high heat in a large pot. Add thinly sliced mushrooms, then cook, stirring occasionally. Add ginger paste and cloves of garlic. Stir well, then cook.
Pour in water, then bring to a rapid boil. Add soy sauce, mirin, hondashi powder, crumbled seaweed, and cubed tofu. Stir well. Allow the soup to come back up to a boil, then lower the heat to a simmer and cook.
If you’re adding any greens, stir them into the soup, then cook.
Turn off the heat. Place miso paste in a fine mesh sieve, then lower that into the soup. Use a spatula or small whisk to help dissolve the miso pasta into the water. Finish with thinly sliced green onions, then enjoy!