How to Make It
To prepare broth, combine first 3 ingredients in a large stockpot; bring to a boil. Reduce heat, and simmer 2 hours. Add 2 tablespoons parsley and next 5 ingredients (through parsnip) to pan; simmer 1 hour. Strain broth through a sieve into a large bowl. Reserve 2 carrot halves; thinly slice, and set aside. Discard remaining solids. Cover and chill broth overnight. Skim solidified fat from surface; discard.
To prepare matzo balls, combine matzo meal and next 7 ingredients (through grated nutmeg) in a large bowl; cover and chill 4 hours or overnight. Lightly coat hands with water. Roll matzo mixture evenly into 16 balls. Gently drop balls into simmering water, and cook 20 minutes or until done (matzo balls will rise to surface). Remove from water with a slotted spoon.
Transfer broth to a large Dutch oven. Add zucchini, 1/2 teaspoon salt, pepper, and reserved carrot to pan; bring to a boil. Reduce heat, and simmer until reduced to 8 cups (about 5 minutes). Add cooked matzo balls to pan; cook 2 minutes or until thoroughly heated. Remove from heat; sprinkle with 1 tablespoon dill.