1. Bring 1 1/4 cups broth, 2 teaspoons oil, and 1/8 teaspoon salt to a boil in a medium saucepan. Stir in couscous; cover. Remove pan from heat.
2. Combine remaining 2 teaspoons olive oil, remaining 3/8 teaspoon salt, rosemary, garlic powder, and pepper in a bowl. Rub paste evenly on both sides of chops. Heat a skillet over medium-high heat. Coat pan with cooking spray. Add lamb; cook for 6 minutes or until desired degree of doneness, turning once. Remove from pan, and keep warm.
3. Add remaining 1/4 cup broth, jelly, vinegar, and mustard. Bring to a boil. Reduce heat; simmer for 90 seconds or until slightly syrupy.
4. Fluff couscous with a fork; stir in pistachios, and sprinkle with mint. Spoon sauce over lamb. Garnish with rosemary leaves, if desired.