Steps :

1. Wash lentils and soak in lukewarm water for 2 hours.
2. Drain the lentils.
3. Add 6 cups of water in a saucepan.
4. Add lentils.
4. Slice the onion and add.
5. Add cloves of garlic.
6. Bring water boil and cover.
7. Add 1 tablespoon of tomato paste and stir well.
8. Lower the heat and simmer for 30 minutes.
9. Add olive oil.
10. Add salt.
11. Add 1 tablespoon of tomato paste and stir well.
12. Add 2 bay leafs.
13. Add 2 tablespoons of vinegar.
14. Simmer for an additional 10 minutes.
15. Check if lentils are tender and allow for slightly more time if not.

Notes : You can experiment with the amount of lentils to achieve your desired taste and texture of the soup.