Heat oil in a Dutch oven over medium-high heat. Add lamb; cook 5 minutes or until browned, stirring frequently. Stir in onion and next 5 ingredients (onion through turmeric); cook 5 minutes. Stir in tomato and next 5 ingredients (tomato through pepper). Bring to a boil; cover, reduce heat, and simmer 35 minutes. Uncover; simmer 30 minutes.
Prepare couscous according to package directions, omitting salt and fat.