Step 1

In a small bowl, stir together 1 teaspoon of the cumin and 1 teaspoon salt. Set aside. Season the chicken on both sides with salt and pepper.

Step 2

In a large Dutch oven over medium-high, heat the oil until shimmering. Add the onions and garlic and cook, stirring, until lightly browned, about 5 minutes. Add the remaining 3 teaspoons cumin, the turmeric, ginger and coriander, then cook, stirring, until fragrant, about 30 seconds. Stir in 1½ cups water and the saffron, scraping up any browned bits. Nestle the chicken into the liquid, turning to coat. Cover, reduce to medium-low and cook for 20 minutes at a gentle simmer.

Step 3

Using tongs, turn the chicken. Cover and cook until tender, another 25 minutes. Using tongs, transfer the chicken to a plate. Bring the liquid in the pot to a simmer over medium-high and cook, stirring, until thickened, 10 to 14 minutes.

Step 4

Return the chicken to the pot and stir. The chicken will break up a bit. Off heat, add the butter, stirring until melted, then stir in the olives and lemon zest and juice. Taste and season with salt and pepper. Transfer to a platter and serve with the cumin-salt mixture to sprinkle over, to taste.