Spray 5-quart slow cooker with cooking spray. In large resealable food-storage plastic bag, place flour, 1/2 teaspoon of the salt and the black pepper. Add lamb; seal bag and shake to coat with flour mixture. In 12-inch skillet, heat oil over medium-high heat. Cook lamb in oil 5 minutes, stirring occasionally, until browned. Place onion and garlic in slow cooker; sprinkle with curry powder and red pepper. Place lamb over vegetables. Pour broth over lamb.
Cover; cook on Low heat setting 6 hours. Stir sweet potatoes into stew. Cover; cook 2 hours longer or until lamb and potatoes are tender. Gently stir in whipping cream and remaining 1 teaspoon salt. Serve stew over couscous. Garnish with peanuts and parsley.