Aunt gillie`s matzo ball soup

For the soup:
1 3-lb., chicken
3 Carrots halved
2 medium yellow Onions, peeled and halved
5 stalks Celery, with leaves, halved
3 Parsnips, halved
2 Leeks, well cleaned, white parts only
1 head Garlic, unpeeled, split
4 stalks fresh Dill
1 bunch Parsley, washed
For the matzo balls:
1 medium yellow onion, peeled and halved
8 Eggs
8 tbsp. Margarine, melted and slightly cooled
2 1/2 cups matzo meal
2 tbsp. finely chopped Parsley
Salt and freshly ground black Pepper
Small dill sprigs

TO MAKE THE SOUP:
Combine chicken, Carrots, Onions, Celery, Parsnips, Leeks, Garlic, Dill, Parsley in a large stockpot with water to cover. Bring just to a boil over medium-high heat. Skim foam. Reduce heat to low and simmer for 2 1/2 hours. Strain and discard solids (chicken may be reserved for another use), then cool to room temperature. Refrigerate for at least 3 hours, then remove any solidified fat from the surface.
TO MAKE THE MATZO BALLS:
1. Grate enough onion to yield about 2 tbsp. and set aside the rest. In a large bowl, combine grated onion, Eggs, Margarine, matzo meal, Parsley, and 1/4 cup water or chicken soup. Mix well, season with Salt and Pepper and set aside to rest for at least 30 minutes.
2. Wet hands and roll dough in your palms into 23 2" balls (they will expand as they cook). Meanwhile, bring a large pot of water to a boil. Add 2 tbsp. salt and remaining onion. Drop matzo balls into water one at a time. (They won`t stick together if the pot is large enough.) Reduce heat, cover, and simmer 30-40 minutes. Drain, remove to a plate and cover, until ready to use. (Matzo balls will keep up to 3 days in the refrigerator.)
3. To serve, heat soup over medium heat and season to taste with salt and pepper. Add matzo balls and heat through. Garnish with Dill sprigs.