This is a very easy sauce to make and much tastier and more economical than the purchased bottled variety. The vegetable stock can be substituted for pineapple juice or just plain old water. I use the juice when I am making a stir fry that I will throw some pineapple pieces into. You can vary the ingredients to your taste. To make this sauce gluten free, ensure that you use a GF stock, soy sauce and maize cornflour. White Wings cornflour and Fountain soy sauce are currently gluten free in Australia. The sauce will keep easily for a week in the refrigerator