Saute it on high heat until it gets a glassy / translucent look then turn the heat down to low-medium.
Cook it until the onion gets a brownish caramelized look while stirring every now and then.
Add the cumin, crushed garlic, tomato and saute it until garlic gets fragrant.
Add paprika, celery leaves.
Add the water.
Add the optional vegetables and simmer it until the vegetables gets almost done for about 10 minutes.
Beat eggs in a bowl. Optionally, eggs with whole yolks can be added into the soup.
Add the eggs to the soup.
Cook it ready for about 3 minutes. Whole yolks need more time and they don't like to be disturbed much.