For the Chicken: 2 tablespoons (30 ml) olive oil 1 tablespoon (15 g) unsalted butter 1 medium onion (8 ounces; 226 g), diced 1 1/2 teaspoons ground turmeric 1 1/2 teaspoons ground ginger Light pinch of saffron threads (optional) 1 1/2 teaspoons Diamond Crystal kosher salt, plus more to taste; for table salt, use half as much by volume 1/4 teaspoon ground black pepper 2 1/2 pounds (1.13 Kg) skin-in on, bone-in chicken thighs (alternatively, use bone-in skin on chicken pieces
