Heat the olive oil in a large pot over medium-high heat
Add the beef and season with salt and pepper, cook until brown, about 10 minutes.
Using a slotted spoon, transfer the beef to a large bowl.
Add in carrots, celery, garlic, onion, rosemary and oregano. Sauté veggies until the onions are tender and translucent, about 10 minutes.
Add back in the beef and and juices.
Add in the tomatoes and broth.
Reduce heat to medium-low. Once the soup is at a low simmer, cover and let cook for about an hour until the beef is tender. Stir occasionally while the soup is cooking.
Once the beef is to your desired tenderness, add in the lentils.
Cover and continue to simmer, while stirring occasionally until the lentils are tender, about an hour.
Add in salt and pepper to taste, ladle into soup bowls and serve.
