Dice the onions, cut the carrots, parsnips into rounds or half moons, dice the celery stalk (or celery root), chop the parsley, and cut the cauliflower into florets
Sauté the onion in a medium to large pot on medium. Once the onion is transparent, add the chopped carrots, parsnips and celery. Add about 3 tbsp of water, reduce the heat to medium low, cover and simmer for about 6-7 minutes. Stir it occasionally and add a bit of water if necessary.
Once the veggies are fork tender, but not too soft, remove the pot from the heat, and add the 1 tbsp flour, the 1 tsp sweet paprika, and mix it together.
Add 2 L ( 8 cups) cold water, the cauliflower florets, salt, pepper, and most of the chopped parsley (reserve some for garnish). Bring it to a boil, then let it simmer semi-covered on medium-low heat until the florets are fork tender.
Once the dumplings are added and floating on the surface, remove the pot from the heat. See below for dumpling recipe and instructions.
Optional but recommended: Mix 2 tbsp sour cream with the 2 tbsp cold water, then add 2 tbsp soup to it, and mix. Pour it into the soup, and stir.