Thinly slice lemon crosswise into rounds. Cut rounds into quarters. Place lemon in a small saucepan with water just to cover and stir in 1 tablespoon kosher salt. Bring to a boil, then reduce heat and simmer for 5 minutes. Drain well and rinse lemon under cold water.
Heat 3 tablespoons of oil in a Dutch oven or large, deep skillet or over medium high heat. Dry the chicken pieces and season them with remaining 1 1/2 teaspoons kosher salt and the pepper. Place them in the skillet in batches and brown on all sides, about 10 minutes. Remove the chicken and place on a paper towel lined plate.
If skillet looks dry add the remaining tablespoon oil. Add the onion to the skillet and cook until slightly softened. Add the ginger, garlic, coriander, cumin, paprika, turmeric and cayenne pepper and stir together. Cook 1 minute longer.
Add the chicken pieces and stir to coat with the spice mixture. Pour the chicken stock into the skillet so that 2/3 of the chicken is submerged. Add the saffron and stir to combine. Bring liquid to a simmer, cover the skillet and simmer on medium low heat 20-25 minutes.
Add the olives, lemon slices, and dried fruit if using, stirring to combine. Cover and cook another 10 minutes or until chicken is cooked through.
Transfer chicken to a serving platter. Raise heat to high and boil sauce, uncovered, until thickened, about 10 minutes. Stir in cilantro and spoon sauce over chicken to serve.