Step 1

In a small bowl, combine the tamarind pulp and boiling water; stir with a fork to break up. Cover and let stand for 30 minutes. Strain through a fine-mesh sieve set over another small bowl; press on the solids and scrape the underside of the sieve to collect the pulp that clings. Set aside; discard the solids in the sieve.

Step 2

Meanwhile, in a large Dutch oven over medium, toast the peanuts, coconut and sesame seeds, stirring, until golden and fragrant, 3 to 5 minutes. Transfer to a blender and set aside.

Step 3

In the same Dutch oven over medium-high, heat 2 tablespoons of the oil until shimmering. Add the onion and 1 teaspoon salt; cook, stirring occasionally, until lightly browned, 7 to 9 minutes. Stir in the ginger and garlic; cook, stirring, until no longer raw, about 1 minute. Add the garam masala, chili powder and turmeric; cook, stirring, until fragrant, about 30 seconds. Add 1 cup water and scrape up any browned bits, then transfer to the peanut mixture in the blender; reserve the pot. Blend on high until thick and smooth, scraping the blender jar as needed, 1 to 2 minutes; set aside.

Step 4

Set the Dutch oven over medium and add the remaining 2 tablespoons oil, the mustard seeds, cumin seeds and curry leaves (if using). Cook, stirring, until fragrant and sizzling, 1 to 1½ minutes. Add the puree and bring to a simmer over medium-high; cook, stirring, until very thick, 2 to 3 minutes.

Step 5

Stir in the tamarind liquid and 1 cup water, then add the chicken. Simmer, uncovered and stirring occasionally, until the chicken is no longer pink when cut into, about 8 minutes for breasts or 13 minutes for thighs. Off heat, taste and season with salt and pepper. Serve sprinkled with cilantro.