Kibbeh Hamdah (Tangy Meatball Soup With Lemon and Celery)

Ingredients

• ½ pound ground lamb
• ¼ cup cold water
• ½ teaspoon ground allspice
• ½ teaspoon ground cinnamon
• 1½ teaspoons kosher salt
• ½ cup finely chopped flat leaf parsley leaves
• ⅔ cup long-grain white rice, finely ground in a coffee or spice grinder (you can use rice flour if you don't own a grinder)
• ½ pound ground beef
• 8 to 10 cups beef or lamb stock
• 2½ cups celery, coarsely chopped
• 1¼ cups finely chopped scallions or white onions
• 2 tablespoons garlic, finely chopped
• ½ cup flat leaf parsley, finely chopped
• 1 cup carrots, coarsely chopped
• 1 cup white potatoes, peeled and cubed
• About 1 teaspoon kosher salt (amount depends on how much salt is already in your stock!)
• Freshly ground black pepper
• 1½ tablespoons dried mint
• ¾ cup freshly squeezed lemon or lime juice
• 1 large yellow squash or zucchini, stem and end discarded