From Padma's All American Cookbook (library book).
Not pretty to look at
Place the chicken thighs on a cutting board and make 3 even slits
¼ inch deep across the top of cach thigh. Sprinkle the thighs with 1½ teaspoons kosher salt and use your hands to rub it over the chicken. Transfer to a large bowl and let rest at room temperature.
Meanwhile, heat a small dry skillet over medium heat. Add the peppercorns and roast until fragrant, stirring for 1 to 2 minutes.
Transfer to a mortar and pestle or spice grinder. Add the cumin seeds to the skillet and toast until fragrant, 1 to 2 minutes. Transfer the cumin seeds to the same mortar and pestle or spice grinder and grind both into a fine powder.
Transfer that pepper/cumin mixture to the bowl with the chicken.
Add the onions, yogurt, lemon juice, garlic, ginger, garam masala, cayenne, amchur, turmeric, and 2 teaspoons kosher salt. Mix with your hands, rubbing everything into the chicken. Cover and let the chicken marinate for 30 minutes at room temperature. (You can also cover and refrigerate for up to 8 hours or overnight. Bring to room temperature for 30 minutes before baking.)
Preheat the oven to 450°F. Spread the oil over the bottom of a
9 x 13-inch baking dish.
Pour the chicken and yogurt mixture into the dish, arranging the chicken in a single layer. Bake uncovered until the chicken is cooked through, 20 to 30 minutes. Serve warm with rice. Garnish with cilantro