Start boiling the beef for 2 to 3 hours, until tender. In a sauce pan heat the olive oil and add the carrots, onion and celery and saute until tender. Do not burn.
After the meat has been properly boiled, add the onion, cauliflower, and carrot mixture to the beef and broth. Add the tomato paste, juice from one lemon, salt and pepper to taste, add the rice and let simmer for another 30 minutes. 5 minutes before it's done, add zucchini.
After 30 minutes, add the egg to the soup, it should end up looking like pasta in your soup. Take off heat and add chopped parsley. Serve hot with sour cream. It's delicious on a cold winter night.