We preferred kosher chicken broth in this soup because it imparts a deep, rich flavor, but feel free to use whatever you have on hand. Kosher chicken broth is relatively available in most grocery stores in the kosher or Jewish food aisle. You may need to find kosher chicken breasts from a kosher butcher or grocer. However, both products are available online.
1. Combine first 7 and, if desired, chicken, in a large Dutch oven. Tie together parsley and next 3 ingredients with a string, and place in Dutch oven. Bring mixture to a boil over medium-high heat; cover, reduce heat, and simmer 30 minutes.
2. Remove herbs, and discard. Ladle soup into bowls, and add 2 matzo balls per serving.