In a large pot, bring the chicken broth or water to a boil.
Add the chicken pieces and cook until they are tender and cooked through, about 30 minutes.
Remove the chicken from the pot, let it cool slightly, and then shred the meat, discarding the bones. Set aside.
In the same pot, add the finely chopped onion, diced carrots, diced parsnips, diced celery root, and minced garlic.
Simmer the vegetables in the chicken broth until they are tender, about 15-20 minutes.
In a separate small pan, melt the butter over medium heat.
Stir in the flour to form a roux and cook for about 2-3 minutes until it is lightly golden.
Gradually whisk in a cup of the hot chicken broth to the roux, stirring constantly to avoid lumps.
Pour the roux mixture back into the pot with the vegetables and broth, stirring well to combine.
Add the okra and shredded chicken to the pot.
Season with ground black pepper and salt.
Simmer for an additional 10-15 minutes until the okra is tender.
In a small bowl, whisk together the sour cream, egg yolks, and lemon juice.
Temper the mixture by adding a ladleful of the hot soup to the bowl, stirring constantly.
Gradually stir the tempered egg mixture back into the pot, making sure the soup is not boiling to prevent curdling.
Ladle the begova čorba into serving bowls.
Garnish with freshly chopped parsley.
Enjoy your meal!