Cook soba noodles according to package instructions, drain and set aside.
In a large pot, heat olive oil over medium heat. Add onion and garlic, sauté until translucent.
Add mushrooms and tofu, cook for 5 minutes. Pour in vegetable broth, bring to a boil. Reduce heat and simmer for 10 minutes.
Stir in soy sauce and miso paste until well combined.
Add leafy greens and wakame, cook until wilted.
Divide noodles into bowls, pour soup over noodles.
Garnish with radish slices and season with salt and pepper to taste.