Pour the broth into the pot along with the coconut milk and add the garlic, ginger and crushed whole stalks of lemongrass, kaffir lime leaves and whole chili peppers. Bring the whole to a boil and cook on low heat for about 15 minutes, then strain the broth with milk and set aside.
In the second pot, heat vegetable and sesame oil and fry the onion. Add turmeric, sugar and fry for another 5 minutes over low heat. Set the caramelized onion aside and mix the cauliflower roses into the pot and fry them until golden for about 3-5 minutes.
Then pour the broth with coconut milk, lime juice and soy sauce into the cauliflower pot. Cook the whole thing for 10-15 minutes until the cauliflower is soft. Serve with garnished spring onions, coriander and caramelized onions.