Make the chicken broth: peel the carrots, parsley root, celeriac, and onion. Cut into large chunks. Add the vegetables, spices, and chicken pieces into a large pot. Add 8 cups of cold water. Bring to a boil, reduce the heat to low, and simmer, partially covered, for 1 hour.

Strain the broth, discard the vegetables (you can leave carrots if you like them, slice them and add to the soup), set the meat aside to cool. When the meat is cool enough to handle, you can take the meat off the bones and add it to your soup or leave it for other uses.

Add the tomato puree to the broth. Bring the soup to a boil then take it off the heat.

Temper the cream: Add both types of cream to a cup, add a tablespoon of hot soup to the cream, stir until combined, gradually add more soup to the cream, stirring thoroughly after each addition. You should add about 8 tablespoons of soup in total. If the sour cream is still lumpy you can process the mixture in a food processor or press it through a fine-mesh strainer.

Add the tempered cream to the soup. You can now warm up the soup but don't boil it (the cream can split).

Season the soup with salt and pepper. You can add more cream if you wish. You can add heavy cream directly to the soup but sour cream needs to be tempered first. If your soup came out too sour you can add a teaspoon (or to taste) of light brown sugar.

Serve with cooked pasta or rice. Sprinkle with chopped parsley.

Enjoy!