In shallow pan, add the couscous. Bring water to a simmer and pour over the couscous. Cover and let sit until all of the liquid as evaporated, about 5 minutes. In a small saute pan, melt the butter over medium heat. Add the onions. Season with salt and pepper. Saute for 1 minute. Stir the onions, pine nuts, preserved lemons and parsley into the couscous and serve.
Slice each lemon in half. In a mixing bowl, toss the lemons generously with salt. Place half of the lemons in the quart jar. Juice the remaining lemons and pour into the jar. Fill the jar to the top. Secure the lid and let sit in a cool dry place for at least 3 days. The lemons, can set longer and will keep in the refrigerator.