Makes 24 matzo balls Serves 8 as a starter FOR BROTH 3 pounds bone-in, skin-on chicken parts 2 large onions, unpeeled, quartered 4 celery stalks, 2 large carrots, rough chop Kosher salt In a large soup pot, combine all the ingredients except the salt, with 12 cups of cold water and bring to a boil over high heat. Reduce heat to medium and simmer, uncovered, for 2 hours. After two hours, using tongs, remove just the chicken. When it is cool enough to handle, pick the meat from the chicken, discarding the skin, bones and cartilage. Set the meat aside. Strain broth and then pour it back into the pot. Season with salt. Let it cool completely and then refrigerate overnight. As it cools, any remaining fat will float to the top. Do not stir that back in. When it is solid, carefully lift or skim the fat off of the broth and set aside to use with the matzo balls. FOR SOUP 4 large eggs, room temperature 1 cup matzo meal ½ cup chopped, fresh dill fronds (no stems) ¼ cup chicken fat, from the broth 2 teaspoons kosher salt ¼ teaspoon ground black pepper 1 ½ cups seltzer water 10 cups defatted chicken stock 2 large carrots, peeled and sliced on the diagnol (or 12 baby carrots, trimmed) Dill fronds for garnish In a medium bowl, whisk together the eggs, then add the matzo meal, dill, fat, salt and pepper and stir to combine. Add the seltzer water slowly, mixing to incorporate. Cover and refrigerate for at least 3 hours and up to 24. When ready to finish the soup, bring 6 cups of well salted water to a simmer. Lightly oil your hands and form the matzo mixture into golf-ball sized balls (they expand, don’t worry). You should have about 12. Add the balls to the simmering water and let cook for 1 hour, stirring a few times to make sure they don’t stick together. Once the matzo balls have been cooking for 45 minutes, bring the chicken stock to a simmer and add the chicken and carrots. Using a slotted spoon, transfer the matzo balls to the simmering broth, season and let simmer for another 5 minutes so the chicken heats through. To serve, ladle 3 matzo balls into 4 warmed, shallow, soup bowls. Garnish with the chicken and carrots and some dill. If you are making the soup ahead, store the broth and the matzo balls separately. Both components can be frozen for up to 3 months.