1 medium zucchini (1/2 lb), coarsely grated (about 1 cup)
1/4 teaspoon dried mint, crumbled
Special equipment: a well-seasoned large (2-burner) ridged grill pan
Directions
Heat lightly oiled grill pan over moderately high heat until hot but not smoking.
Meanwhile, toast curry, turmeric (if using), cinnamon, and 1/4 teaspoon pepper in a small heavy saucepan over moderate heat, stirring constantly, until fragrant, about 1 minute. Add water, 1/2 teaspoon salt, and butter and bring to a boil. Place couscous in a heatproof bowl and pour in boiling water mixture, then quickly cover with a plate or plastic wrap and let stand 5 minutes.
While couscous stands, pat chops dry and sprinkle on both sides with 1/4 teaspoon salt and remaining 1/4 teaspoon pepper. Grill chops, turning over once, about 6 minutes total for medium-rare. Transfer to a serving plate.
For raita, stir together yogurt, zucchini, mint, and remaining 1/2 teaspoon salt.
Fluff couscous with a fork and serve with lamb and raita.