2. Reduce the heat. Add the onion and garlic to the pan, adding a little extra oil if necessary and cook until the onion begins to soften. Add the cumin, coriander and tomato paste, stir and cook for a further minute. Pour over Wattie's Just Add Butter Chicken Simmer Sauce.
Allow the sauce to come to the boil. Reduce heat. Simmer for 20 minutes or until chicken is cooked and sauce reduced by a third. Remove from the heat. Stir through chopped coriander and allow to cool. Refrigerate until cold.