Marinate the beef with salt,black pepper, vinegar cover n let it sit on a refrigerator for approx 1-4 hrs.

Heat the grill pan until very hot,then add the meat sprinkling a mixture of water n vinegar or salt. Keep turning to ovoid burning the meat.

Once the meat is ready cover with a foil.

Grill onions and capsicum in the pan and serve with the meat.