Heat 2 tablespoons extra-virgin olive oil, 2 turns of the pan, in a large skillet or Dutch oven over medium-high heat. Add the onions, bay leaves and garlic and season with salt and pepper, to taste. Stir for 3 to 4 minutes, then cover the pan and sweat the onions for3 to 4 minutes more. Uncover the pot and stir in the olives.
Meanwhile, heat 1 tablespoon butter in a medium-high sided skillet over medium to medium-high heat. Slice 2 lemons and gently brown the slices, in 2 batches. As they brown, add them to the pan with the onions. Add 3 more tablespoons butter to the pan and let it melt, then add saffron threads and the zest of l lemon to the melted butter and stir for 1 minute. Whisk in the flour, cook for a minute more, then whisk in 2 1/2 cups of the chicken stock. Season the sauce with turmeric, cumin and cinnamon and let thicken for a couple of minutes. Stir in the juice of remaining 2 lemons and reduce the heat to low. Add the chicken and sauce to the onions and gently stir to combine. Cool and store for a make-ahead meal or, cover the pan to warm the chicken through and combine flavors.
When ready to serve, prepare couscous. Put the remaining 1 tablespoon of butter in a medium pot or pan with tight-fitting lid and let it melt over medium heat. Add the pine nuts and gently toast them to light golden brown. Stir in the remaining 1 1/2 cups of chicken stock and bring it to a boil. Stir in the couscous, turn off heat, cover the pan and let stand for 5 minutes. Fluff the couscous with a fork and add the mint and parsley. Spoon the couscous into a serving bowl.
Transfer the chicken mixture to a serving bowl or platter and serve with the couscous.