First grind together non-fried onion, ginger, garlic and chilly powder into a smooth paste.
Soak dry red chillies in vinegar. Bring it to boil for 2 minutes and grind well.
Heat oil in a deep bottomed pan and fry the ground paste for about 10 minutes in low heat. If mixture sticks to bottom of pan, add little water.
Cook till the paste becomes golden brown and oil separates.Add chilly paste.
Stir in dried beef pieces, ground pepper and chopped lemon grass.
Continue frying till the beef becomes brown and water evaporates completely.
Add hot water, required salt and cook with a covered lid.
When the beef pieces are well coated with gravy, remove pan from fire.
Dry beef stir fry is ready. Garnish with fried onion and serve hot with white rice.