Preheat the oven to 350 degrees . Season the chicken with salt and pepper. In a medium saucepan, bring the chicken broth to a boil with the apricots, prunes and orange peel. Reduce the heat and simmer, uncovered, for 15 minutes.
Meanwhile, in a Dutch oven or a deep ovenproof skillet, heat the oil over medium-high heat and brown the chicken in 2 batches, skin side down. After about 5 minutes, turn the pieces over and brown the other side, about 2 minutes. Remove the chicken to a plate. Pour off all but about 2 tablespoons of the fat, add the onion and garlic and saute over medium heat until slightly softened, about 2 minutes. Stir in the tomato paste and cook for 1 minute longer. Stir in the fruit-and-broth mixture, scraping to loosen any brown bits that have stuck to the bottom or sides of the Dutch oven. Season with salt to taste.
Transfer the thighs and their juices to the broth. Return to a simmer, then bake, uncovered, for 25 minutes. About 10 minutes before the chicken is ready, prepare the couscous according to the package instructions. Spoon the stew over the couscous and serve.