Weigh and arrange all ingredients for use.
Peel and chop the onion.
Cut the meat into slices, about 1cm thick.
Place the meat slices on top of each other and cut into small strips.
Pour some oil into a hot pan and fry the meat in batches. Remove from the pan when browned.
Add the butter to the pan and fry the onion, stirring occasionally.
Sprinkle in the flour and cook, stirring for 1 minute.
Add the white wine and bubble until reduced, stirring occasionally.
Add the stock and simmer for a few minutes.
Stir in the cream. Grate a little lemon zest. Season the sauce with lemon zest, salt and pepper.
Return the meat to the pan and heat until cooked through.
Season with salt, pepper and lemon juice. Wash the parsley, shake dry and chop finely. Sprinkle over the stew and serve with rosti if desired.