This recipe focuses on the chicken soup that is served together with the matzah balls. You'll want to make the matzah balls separately, then serve this soup together with the matzah balls.

• For the first pound of celery, cut it into large 1-inch chunks (you can include any celery leaves as well).
• The rest of the celery and the carrots (which will end up in the finished soup that is served) should be sliced no thicker than 1/2 inch, with larger stalks and carrots halved lengthwise before cutting into chunks. The uniform size will ensure the pieces cook quickly and evenly. Reserve. (By the way, these veggies are optional - some people like their chicken soup without any vegetables.)
• If using saffron, crush the saffron threads in a mortar and pestle until pulverized to powder. Note: saffron adds a depth of flavor and a deep golden color to the broth. The soup will be delicious with or without it.
• Remove the root end of the onion (it can sometimes be a bit dirty), then slice the whole onion into two halves. Leave the skin on, but make sure it is rinsed clean.
• If using a whole chicken, make sure any gizzards that might be hidden inside are removed (they'll make the stock murky and cloudy). Place the chicken into a 10 quart or larger stock pot. Cover with 5 quarts (20 cups) of water.
• Bring water to a boil over medium high heat. Let the chicken simmer for 10-15 minutes, skimming the foam and particles that rise to the surface of the water periodically, until most of the foam is gone.
• Replenish the liquid that was removed during scumming with hot water (it's usually around 1-2 cups).
• Do a final skimming to remove any leftover foam. Add the first pound of celery (the larger pieces), onion, parsley (unchopped), 2/3 of the dill (unchopped), peppercorns, cloves, and bay leaves to the pot. Add 1 tbsp kosher salt to the water (if you're salt sensitive or using a kosher salted bird, you may wish to salt less). Bring back to a simmer. From this point on, it's important not to let the soup come to a rolling boil. A slow and even simmer is best - if the soup boils quickly, the broth may become cloudy.
• If you are adding the saffron, add it to the pot now. Spoon a little of the hot water from the pot into the mortar, stir, then pour it out to make sure you get every bit of saffron into the pot.
• Put the lid on the pot and vent it. Reduce heat to medium low so the soup is slowly simmering. Let the soup cook for roughly 90 minutes.
• Test for doneness by pulling the leg from the chicken. It should easily separate, showing that the chicken has become quite tender. If not using a whole chicken, stick a fork into one of the dark meat pieces to see if it flakes tenderly. When chicken is ready, turn off the heat. Use a pair of tongs to carefully pull the chicken from the broth (it may fall apart into pieces as you pull it out - that's a good sign!). Put it on a plate or in a bowl.
• Allow the chicken and the broth to cool down for 20-30 minutes, until the pot handles are cool enough to touch and lift. Carefully strain the broth into another pot or large bowl (6 quart) through a mesh strainer. Discard the celery and onion (which will be very mushy and flavorless at this point), spices, herbs, and onion halves. If you used a bowl here, clean the pot and add the strained stock back to the pot again - it will need to cook a little longer.
• Pull the meat from the chicken bones into bite-sized pieces.
• Now is the time to add the reserved fresh sliced veggies to the pot (1 pound celery, 1 pound carrots). Bring the broth to a simmer - not a boil - and let the vegetables cook for 20-30 minutes until tender. (If you're not adding additional veggies, just skip ahead to the next step).
• Remove stems from the remaining fresh dill and chop it up.
• Stir the cooked chicken pieces and the dill into the soup with the vegetables, and simmer for a couple of minutes more. Taste the chicken broth and season with additional salt, if desired.
• Serve individual portions of soup ladled over the matzah balls. Add about 1.5 cups of soup per bowl, and 2 matzo balls per serving (depending on the size of the matzah balls).