In a large nonstick skillet, heat the oil and fry the onions and garlic until they are soft. Add the crab meat and allow to braise slightly.
Add the tomatoes. Once cooked through add the coconut milk, salt, pepper and palm oil and simmer for a bit to allow flavors to meld.
Remove the contents from the heat and gradually add the flour. Stir well and return to low heat, stirring until the bottom of the pan starts to appear.
Add the parsley and chives and then turn off the heat. Put the dough inside the crab shells/containers.
Mix the breadcrumbs and the grated cheese. Sprinkle the crab shells/containers with cheese mixture.
Bake at 425 degree until gratin is golden (10 minutes on average). Serve the crab shell with lemon wedges.