Boil the salt fish 2 times discarding the water once it has boiled for 5 minutes. Return to fire and bring to a boil and add in ackee. You can boil in separate pot too.
Remove from heat and sit in ice water. Break up up fish and remove bones when it has cooled enough to handle it.
Dice your onions and tomatoes and put in a pot with medium heat.Use 1 tbsp of oil so onions can caramelize or water. Once caramelized, stir in ackee and salt fish, seasoning to taste with black pepper and salt.