When hunting for great food in the bylanes of Kolkata in my teenage years, one thing that we would often go looking for was the famed mutton rezala. Aminia, Nizam and many other places did good rezalas, but the most famous one was Shabir in Kolkata's Chandi Chowk area. I've been back to Shabir a few times over the years, but this time I went to the second-greatest rezala place in Kolkata - New Aaliya on Bentick street, very close to Statesman House - and came out licking my fingers for the next month.
Rizala originates from Lucknow (and is even listed in Dastarkhan-e-Avadh by RK Saxena) but seems to have survived in Kolkata in a unique variant (and its not just the spelling that changed); I've never seen quite the same thing in any other city. Though RK Saxena's authoritative Avadhi recipe describes it as a thick white gravy, Rezala - its Kolkata variety - is spicy, thin and just a little sweet. Awadhi Rezala is made with mutton but in Kolkata, the chicken variety is just as common.
Anyway, the reason for all this rezala rumination is that I was hankering for it last weekend and decided to reproduce it. Googling yielded a few recipes, but none of them looked like they would yield anything like the alsi Kolkata variety, so I decided to combine google with me and try things our from taste memory. The thing about taste memory is, of course, that the broad outlines of taste and look get reproduced, but the finer details can vary.
Basically, The Kolkata Rezala is a thin sweet-sour-spicy gravy with a onion-ginger-garlic sauce base, sour curd, whole garam masala, white pepper, a little coriader powder, onion paste and cashew paste - finished with kewra water or a drop of kewra essence. The sour curd and kewra finish are the key taste elements of the Rezala.
The net result was wonderful, though I did add a shade too much white pepper, and the curd wasn't very sour so I added a smidgen of lime juice. And it looks exactly like the New Aaliya variety white a perfectly white sauce base with a floating layer of nearly colourless oil (its actually an oil/water emulsion that contains most of the spice flavouring).