Bring water to a boil in a medium saucepan; gradually stir in couscous, turmeric, and salt. Remove from heat. Cover and let stand 5 minutes. Fluff with a fork.
Heat oil in a large nonstick skillet over medium-high heat. Add eggplant and next 5 ingredients (eggplant through garlic); sauté 4 minutes. Combine eggplant mixture, couscous, chickpeas, feta, and egg. Coat a 9 x 5-inch loaf pan with cooking spray; line with parchment paper, allowing the parchment to extend over outside edges. Spoon couscous mixture into pan, pressing firmly to pack. Fold parchment over top of couscous mixture. Bake at 325° for 45 minutes or until set. Cool on a wire rack 10 minutes. Unfold parchment; invert molded couscous mixture onto a platter. Cool 15 minutes. Slice; serve warm.