For many folk, a trip to the chippy just ain't right without pairing your chips with some British chip shop curry sauce; this homemade version is spectacularly good.
Cut the onion in half, peel it and cut it into a rough 2cm (¾") dice.
Peel and roughly chop the garlic cloves.
Heat the cooking oil in an 18cm or 7" saucepan and when it is hot, add the onions and cook over a medium heat for 10 minutes. If the onions begin to colour, reduce the heat to low.
When the onions have been cooking for 10 minutes, add the garlic and raisins and cook for two minutes.
Pour in the vegetable stock, reduce the heat to low and simmer for 5 minutes.
Mix together the cornflour, curry powder, powdered ginger, turmeric, Chinese 5 spice and asafoetida in a small-medium mixing bowl.
Add a few tablespoons of water from the pan to the cornflour and spice mix and give it a stir to make a slurry.
Transfer the rest of the onion mix to a blender and pulse to a fairly smooth texture, and return it to the pan.
Stir in the cornflour slurry, add the salt, MSG and malt vinegar and have a taste, then adjust the seasoning as necessary. Simmer for a final 5 minutes, then keep warm until your chips are ready, or cool and reheat as necessary.