1. Place the onion and ginger pieces directly on the flame of a gas hob or under a very hot grill until they are slightly blackened all over.

2. Heat a large saucepan over a medium-low heat. Add the cinnamon, star anise, cloves, coriander seeds and peppercorns into the dry pan and stir for 1 minute, until aromatic. Add the vegetable stock, mushrooms, seaweed (if using), charred onion and ginger to the pan and increase heat to medium-high. Bring to the boil and then reduce the heat to medium-low and simmer, covered, for 30 minutes.

3. Meanwhile, bring a large saucepan of salted water to the boil, add the rice noodles and cook according to package instructions until just tender. Drain and refresh under cold running water.

4. Heat a frypan over medium-high. When hot, drizzle with olive oil and add the tofu slices, season generously with salt and black pepper, and cook for 4-5 minutes on each side until golden. Remove from the pan and set aside. Add another drizzle of oil to the pan and add the broccoli and season with sea salt. Cook for 2 minutes on each side until charred. When cool enough to handle, cut the tofu into triangles.

5. After 30 minutes, strain the broth and return the liquid to the pot (discard all the solids). Add soy sauce and sugar, and season with salt to taste, adjusting the seasoning to your liking.

6. Divide the noodles between the four bowls and ladle over the hot soup. Top each bowl with broccoli, tofu, beansprouts, coriander, Thai basil or Vietnamese mint, coriander and jalapeno. Add a wedge of lime to each bowl and serve immediately.

More vegetarian noodle bowls from Hetty McKinnon.