Heat oil in a medium Dutch oven coated with cooking spray over medium-high heat. Add lamb, and cook 8 to 10 minutes or until browned, stirring frequently. Add garam masala, onion, and garlic; cook 3 to 4 minutes or until onion is tender, stirring frequently.
. Combine tomato paste and 1 cup water in a small bowl. Add tomato paste mixture and tomato to Dutch oven. Stir in remaining 1 cup water; bring mixture to a boil over medium-high heat. Add carrot and sweet potato; cover, reduce heat, and simmer 25 minutes or until vegetables are tender. Add okra; cook 5 minutes.
. Remove 1/4 cup cooking liquid from pan; place in a small bowl. Add peanut butter, and stir with a whisk. Add peanut butter mixture to pan; stir in jalapeño pepper, salt, and black pepper. Cook over medium-low heat 15 minutes or until thickened.
. While stew simmers, prepare couscous according to package directions, omitting salt and fat. Serve stew over hot cooked couscous.