1. Combine yogurt, chile powder, turmeric, salt, and 8 pods green cardamom in a large bowl; add chicken, mix, and cover bowl with plastic wrap. Refrigerate for at least 30 minutes or up to overnight.
2. Heat oil in a 6-qt. pot over high heat. Add remaining green cardamom along with peppercorns, black cardamom, and cinnamon; cook until fragrant, 1–2 minutes. Add onions, garlic, chiles, and ginger; cook, stirring and adding a few tablespoons of water as needed, until onions are browned, 12–15 minutes. Add chicken and marinade; cook, flipping chicken occasionally, until most of liquid has evaporated, 20–30 minutes. Add 1⁄3 cup water; bring to a boil. Reduce heat to medium-low; cook, stirring, until sauce has thickened, 6–8 minutes. Season with salt and garnish with ginger, cilantro, and yogurt; serve with rice.