A specialty of the Indian state of Rajasthan, this delicious curry plays the sweet, juicy flesh of the watermelon against a complex background of chiles and spices. For a thicker curry, remove half of the cooked watermelon pieces, blend them to a pulpy consistency, and stir them back into the curry. This recipe is based on one that appears in 660 Curries by Raghavan Iyer (Workman, 2008).