Pressure cook the beef slices with turmeric, salt and enough water. Keep the beef stock aside.
Cut the cooked beef into thin slices.
Add turmeric powder, pepper powder, crushed chilly, garam masala, chilly powder, soya sauce, vinegar, salt, kashmiri chilly powder, ginger, garlic and little beef stock to the mixture. Do not add water. Add corn flour little by little and mix it well. Add beef stock only if necessary and do not make it watery. Keep the marinated slices for 10 minutes aside.
Heat a pan with enough oil to deep fry the beef.
When hot enough, add small batches of beef and fry it. In a few minutes, it will be crispy. If it is fried in small batches, oil won't be absorbed much into the beef. When it is almost done, add curry leaves.
Transfer the fried beef slices onto a paper towel spread in a plate to remove excess oil.
Enjoy the Beef Deep Fry.