Season the fish with salt and pepper. In a stockpot coated with oil, sear the fish. Add the habaneros, onions, garlic, ginger, tomatoes, thyme, bay leaves, and kaffir leaves. Cover with water, check for seasoning and bring to a simmer. Simmer for 1 hour.
Squeeze in lime juice and gai choy right before serving. Check for seasoning. To make the poi, heat the cream with the garlic and ginger and reduce by 20 percent. Add the hot taro and mash together smooth. Season and check for flavor.
Place a mound of poi in the middle of a large pasta bowl. Top off with lots of the fish stew. Garnish with scallions.