Wash the Potatoes and Parsnip. Grate them – either by hand or with a food processor. Finely slice half an Onion.
Squeeze any excess liquid out of the grated/sliced mixture, and mix in a bowl with the beaten Egg, some Salt & Pepper, and some chopped Parsley and a very small sprinkling of Plain Flour
Heat some Olive Oil in a large frying pan (or 2 if you want to multi-task)… Fry spoonfuls of the mixture for 3 or so minutes on each side… You’re after nicely browned, just about in one piece rosti. Don’t disturb them too much at the beginning so they stay in once piece
Use a spatula to lift them out rest on kitchen paper. You can re-heat quickly on a baking tray for 10 mins at 180˚c if you want to make these in advance