Fry the onions until golden brown and soft then dry on a kitchen paper towel. In a food processor or blender, grind the onions to a smooth paste. In a mixing bowl (use glass or stainless steel if available), mix the beef strips with the onion paste, all the spices and the yoghurt (do not add the papaya paste). and set aside overnight or about 8 hours in the refrigerator. Take the marinated beef and mix in the papaya paste. Let stand for about an hour. Thread the beef strips into skewers and grill or broil in the oven for about 20 minutes. Rotate the skewer and grill for another 20 minutes or till done. Best served as wrapped in paratha with a twist of lemon juice, pinch of chopped onions and a pinch of chopped parsley.