1. Char the whole onion (including the skin) and ginger over a gas flame (using a pair of tongs) or place in the oven under the grill heat for 10 mins or so until lightly charred. Once there is some char or colour on the outer skin, remove it from the onion but leave the onion whole.
2. Lightly toast the star anise, coriander seeds and cinnamon stick for 30 seconds in a hot pan.
3. Place a large pot with 50.7 fl oz of water onto a medium heat. Add in the spices, onion, ginger and broth powder, then gently simmer for 20 mins.
4. Prepare the greens, chop and trim them so they're ready to be added. Spiralize the zucchini.
5. Cut tofu into 0.4 inch thick chunks, season with salt and drizzle over a little oil, then sprinkle over sesame seeds on both sides.
6. Gently fry the tofu on each side until it is golden brown. Once cooked, remove from pan and set aside on some paper towel, drizzle with a few drops of sesame oil.
7. Season the broth with fish sauce, coconut sugar, tamari an sesame oil
8. Strain the broth to remove onion, ginger and spices, then add back to the pot, and add in zucchini and any heartier greens that need cooking for 2-3 mins on medium heat.
9. Once greens are cooked, serve into bowls along with the broth, tofu and remaining toppings.