Melt 15 g butter in a large pan (preferably with a lid), add the spices and stir. Then add the fish and fry for a good 1 - 2 minutes on all sides until golden brown. Take out carefully so that the fish doesn`t disintegrate too much and set aside.
Add the remaining butter to the pan and sauté the onions and garlic until the onions are translucent. Add the rice and stir in until it is translucent too. Then add the tomatoes, the stock and the coconut milk. Cover and simmer for 15 minutes.
Stir in the peas, season if necessary and serve the fish on the rice. Cover the whole thing again and cook for another 5 minutes. Then let it steep for a good 5 minutes and sprinkle with the chopped coriander or parsley and serve immediately.