Combine spices, milk, and 500ml of water in a deep pan and simmer for 10 minutes.
Add lamb cutlets to the liquid and simmer gently for 10 minutes, then leave to cool.
Sift flour and cornflour into a bowl and stir in the spices, salt, and chillies.
Beat egg whites until frothy and whisk them into the dry ingredients.
Strain the cooled milk and whisk enough into the flour mixture to create a thin batter.
Coat the lamb cutlets thoroughly in the batter.
Fry cutlets in hot vegetable oil for 3 minutes per side until golden-brown.
Sprinkle with chat masala and serve immediately while hot.