Place the pak-choi in a casserole dish and cover with the coconut milk. Arrange the gambas in and around the cabbage and coconut milk. Sprinkle over some seasoning. Cover with a lid and bring to a simmer over a medium heat.
Once simmering, reduce the heat to low and continue to cook with the lid on for 3-4 minutes until the cabbage is soft and the prawns are pink and tender. Remove from the heat and serve immediately from the dish.