1. Combine mint and sugar in a small bowl, pressing mint into sugar with back of a spoon until blended. Stir in yogurt. Set aside.
2. Combine hoisin sauce and curry powder, stirring well; spread evenly on both sides of pork.
3. Prepare grill.
4. Coat grill rack with cooking spray; place on grill over medium-hot coals (350° to 400°). Place pork on rack; grill, covered, 5 minutes or until done, turning once. Serve pork with yogurt mixture.