Cook the beef and brothPlace the beef and bones in a large pot (or Instant Pot). Add salt, bay leaves, half an onion, and 2 garlic cloves. Cover with water, filling about ¾ of the pot.Cook for about 1 hour, or until the beef is tender.(I often use the Instant Pot to speed this part up.)
Prepare the beefOnce cooked, remove the beef and bones. Discard the bones and shred or chop the beef into small pieces so every spoonful of lentil soup has a little beef in it.
Sauté the vegetablesChop the remaining onion, tomato, and 2 garlic cloves.Heat the oil in a pan, add the carrots, and sauté for 1 minute. Lower the heat, cover, and cook for about 4 minutes, stirring occasionally.Add the onion, tomato, and garlic, and sauté until fragrant.
Cook the lentils Add the lentils directly to the beef broth and cook for about 15 minutes, until they are almost tender.
Finish the soupAdd the sautéed vegetables, chopped beef, and cilantro (whole branches). Let everything simmer together for another 10 minutes so the flavors come together.
Final touchRemove and discard the cilantro branches—they’re just there to flavor the soup.