Clean the baby lamb leg and dry well. Mix jamun vinegar, ginger-garlic paste, salt, pepper, chopped onions, carrot and chilli powder. Apply to the leg and keep aside for six hours, so that the lamb meat absorbs the flavour and taste of the marinade. Put the baby lamb leg on a skewer (sheekh) and cook in a clay oven (tandoor) for 20 to 25 minutes or till done. Season with salt and chaat masala powder.