Prepare the Broth – Place beef bones in a large pot with 3 liters of water. Bring to a boil, skim the foam, then add onions, carrots, parsnip, celery root, and bell pepper. Simmer for 2 hours.
Cook the Tripe – Rinse the tripe thoroughly. Boil it separately for 10–15 minutes, discard the water, then slice into thin strips. Add to the broth and simmer for 1–2 hours until tender.
Season the Soup – Stir in garlic, bay leaves, salt, and pepper. Adjust seasoning to taste.
Prepare the Cream Mixture – Whisk sour cream, egg yolks, and vinegar in a bowl. Slowly ladle in some hot broth, whisking constantly to temper the eggs.
Finish the Soup – Remove pot from heat. Gradually stir in the cream mixture. Return to low heat for 2–3 minutes without boiling.
Serve – Garnish with parsley and serve with bread, extra vinegar, and chili peppers.
