Chop onion and sauté in olive oil. Add chopped celery, cubes of beets and minced garlic and sauté for another minute. Add tomato paste and harissa and mix together.
Add sugar, soup mix, spices and black pepper, white pepper and salt and mix well. Add cold water, cover the pot and bring to a boil.
Cook on medium heat, covered, for about 20 minutes.
Add freshly squeezed lemon juice of half a lemon. Then, add frozen kubbeh carefully, one at a time. Cook for about 20-25 additional minutes.
Allow soup to sit for at least 15 minutes before serving.