In a large pot, sauté onion in oil until soft, about 10–15 minutes. Add garlic and sauté another three to five minutes until fragrant. Add tomatoes, zucchini, celery, water, and chicken soup. Bring to a boil and lower heat. Simmer for 30–40 minutes or until vegetables are soft. Blend with an immersion blender until soft and creamy.

Add chicken drumsticks, marrow bones, shredded carrots, sugar, and spices and bring to a boil again. Lower heat and cook for one and a half to two hours.

Remove marrow bones and discard. Remove drumsticks and cut the chicken from the bones, shredding into bite-sized pieces. Return chicken to soup and serve.