In a small food processor, combine 3 garlic cloves, 2 potatoes, ½ celery root, 1 onion, ½ cup cilantro leaves, and ½ cup parsley leaves. Process until the mixture is smooth and well combined. Set aside.
In a large bowl, add 2 pounds ground beef, 1 teaspoon salt, ½ teaspoon ground black pepper, ½ teaspoon paprika, 1 teaspoon Italian seasoning, 3 tablespoons olive oil, and 1 teaspoon honey. Add the prepared green herbs mixture to the bowl. Knead the mixture with your hands until all ingredients are thoroughly incorporated.
Shape the mixture into approximately 30 meatballs, each about 1½ inches in diameter. Set aside.
In a mixing bowl, combine ½ teaspoon turmeric, ½ teaspoon salt, 4 tablespoons olive oil, 2 minced garlic cloves, juice from ½ lemon, 1 teaspoon honey, and ⅓ cup water. Mix well until all ingredients are thoroughly incorporated.
In a large, oven-safe pot or Dutch oven, heat 6 tablespoons olive oil over medium heat. Add ½ teaspoon turmeric, ½ teaspoon black pepper, and ½ teaspoon salt. Stir to combine. Add 2 onions, cut in halves and sliced, to the pot. Sauté for 2 minutes until they start to soften.
Carefully add the 30 meatballs to the pot right on top of the onion. Arrange the potatoes, peeled and cut into quarters, on top of the meatballs. Pour the lemony sauce evenly over the meatballs and potatoes in the pot. Gently move the pot from side to side to ensure the sauce is distributed evenly.
Cover the pot with a lid and reduce the heat to LOW. Let it cook for 50 minutes, allowing the flavors to meld and the potatoes to become tender.
After cooking, preheat your oven's broiler. Remove the lid from the pot and transfer it to the oven. Broil for 7-8 minutes until the top is nicely browned and caramelized. Remove the pot from the oven and let it cool slightly.
Garnish with ¼ cup chopped fresh parsley and serve.