Bring water to boil in a medium sauce pan. Stir in couscous. Cover and remove from heat. Set aside until all the water has been absorbed, about 5 minutes.

Melt butter In a small shallow pan over medium heat. Add onions, season with salt and pepper. Saute until onions are soft.

Stir onions, nuts, preserved lemon, and parsley into couscous. Fluff with a fork. Serve.