Put all the ingredients into a saucepan and stir it continuously until it thickens.
Alternatively place all the ingredients into a microwave safe jug and stir until combined. Cook it on high for about 5 minutes, stopping it every 30 seconds so to stir as to stop any lumps. You may need to cook it for a bit longer depending on the strength of your microwave.
Thermomix users - place all the ingredients in your TM bowl. Whizz it for 20 seconds on speed 5. Set the temperature to 100, and cook it for 7 minutes on speed 3 (or until thick).
Place into a 1 Litre Sinchies Reusable Food Pouch.