Scotch Beef with Broccoli Stir fry

600g lean Scotch beef rump steaks

150g tenderstem broccoli, thinly sliced

1 x large red onion, thinly sliced

1 x tsp Chinese five spice powder

20ml light soy sauce

2 tsp oyster sauce (this can be substituted with one dessert spoon of Worcestershire sauce)

15g piece fresh ginger, peeled and thinly sliced

1 x large clove garlic, thinly sliced

20g tomato puree

Juice of 1 lemon

50ml sherry or white wine (this can be substituted with 25ml white wine vinegar)

30ml Scottish rapeseed oil - plus extra to fry the steaks, approximately 1 tsp.