Sauté diced onion in Frylight over a high heat for 2 - 3 minutes.
Place the onion in a saucepan and add remaining ingredients. Simmer over a medium heat, stirring often for 10 - 15 minutes until the sauce has thickened.
Allow to cool before storing in the fridge for up to 7 days. Use a good airtight container or bottle.