Marinate the beef: Put the beef in a
medium non-metallic bowl and cover with
the vinegar, soy and Worcestershire
sauce. Leave to marinate for 20 minutes,
or if you have the time, overnight.
Stir fry: Heat a small dry wok until it’s
very hot. Tip in the beef, marinade and
spring onions, stir fry for 2 minutes. Add
the roasted peppers, then stir fry for
a further 2 minutes. Divide the stir fry
between shallow bowls and serve with
some boiled rice.