Austrian meat dumplings (fleisch knödel)

Method

1. Heat the oil in a small frying pan and fry the onion until soft and lightly golden. Leave to cool, then put into the bowl of a food processor with the meat, a good grating of nutmeg and the parsley. Whizz to a coarse mixture. Shape into about 20 small walnut-size balls. Cover and chill.
2. Put the potatoes in their skins in a pan of cold salted water. Bring to the boil, then simmer for 20-30 minutes (depending on size) until tender when pierced with a small knife. Drain and, when cool enough to handle, peel off their skins, then mash the flesh into a bowl using a potato ricer (or push through a large-holed sieve or strainer). Mix with the flours, polenta, egg and butter, then season. Once you have a smooth dough, shape into a log. Wrap in cling film and chill for 2 hours.
3. Put the breadcrumbs in a shallow bowl, then cut the dough into 20 even pieces (about 60g each). Flatten each piece of dough a little, then wrap around each of the meatballs and coat all over with the breadcrumbs.
4. Pour oil into a large pan to a depth of 6cm and heat to about 170°C when tested with a digital probe thermometer. Fry, in batches, for 4-5 minutes, turning, until golden brown and crisp all over. Serve with horseradish mayonnaise.