A more waxy type of potatoes (such as Waitrose Red potatoes, or Charlotte) works best for this recipe, but if you have leftover mash made from a more floury type, they will still be delicious.
More leftover cooked vegetables? Chop them and mix into the spiced potato mix.
The potato filling can be made, covered and chilled for up to 24 hours before making the batter and frying.
When deep frying, always choose a large, heavy pan. It must be no more than ⅔ full with oil, as the oil will rise up in the pan as the food is added.
To test if the oil is hot enough without using a thermometer, simply drop a little of the potato mix into the oil. If it gently bubbles and rises to the surface, it is ready. If it colours too quickly or starts smoking, then the temperature is too hot. If it sinks to the bottom of the pan, it’s not hot enough.
If you have any leftover batter, use it to coat and fry vegetables, much like tempura.