Cut cod into medium size chunks. Cover cod in water. Soak in refrigerator, changing the water 2 to 3 times, every 6 to 8 hours for about one day. In skillet, saute onion until softened, add tomato, peppers, thyme and cod. Saute for 5 minutes and add black pepper to taste. Add ackee and stir gently to combine, simmer until just warmed. Add scallions and salt and pepper, to taste.