Bring water to a boil in a medium saucepan. Stir in couscous, snow peas, oil, and ½ teaspoon salt, remove from heat, cover, and let sit for 5 minutes.
Flake couscous with fork and place in large mixing bowl. Add peaches, pistachios, lime juice, and olive oil. Toss to coat, stir in mint, and season with salt and pepper. Serve cold or room temperature.
