Peel the celeriac, cut into small chunks, and cook in boiling salted water for 15 minutes until soft, once soft remove from the pan and leave them to drain in a colander Dust a plate with a little flour. Divide the mixture into 10 circular patties (about 2cm thick). Put them onto a clean plate dusted with flour and pop them into the fridge for an hour or so to firm up Heat a couple of lugs of oil in a large frying pan over a medium heat, add half the fishcakes and cook for 3 to 4 minutes on each side, or until crisp and golden, then repeat with the second batch Serve straight away, with veg or salad and lemon wedges for squeezing over.