Remove the excess fat and sinew from the
steak. Then cut into cubes of 2.5 cm. Use a small bowl and add the
coriander, cumin, peppercorn, chili powder, mustard seeds, turmeric,
garlic, salt and ginger. Stir to combine and add the vinegar to mix to a
smooth paste. Heat a wok with oil and saute the onion over moderate heat
until just soft. Add the spice paste and stir for 1 minute. Add the meat and cook. Stirring until it is coated with the spice
paste. Add tomato paste and stock. Simmer, cover, for 1 hour 30 minutes, or until the meat is tender.