- Heat the olive oil in a large pot set over medium heat. Simmer the onion for 5 minutes, stirring occasionally, until soft. Add the garlic and continue to cook for 1-2 minutes without browning.
- Meanwhile, put the lentils in another pot and cover with water. Bring to a boil, then drain in a colander.
- Add the lentils to the pan with the onion and garlic, then 1 liter of vegetable stock and the herbs. Stir in the tomato puree and tomatoes, then bring to a boil. Reduce the heat to low and simmer for 40 to 45 minutes, adding more stock if necessary, until the lentils are tender and the soup is thick. Add 1 tablespoon red wine vinegar, then season with salt and pepper to taste. If desired, add another 1 tbsp.
- Ladle into bowls, drizzle with olive oil and serve immediately.
- If desired, sprinkle some feta over the soup before serving.
Tips+: For authentic flavor and texture, use small brown lentils from Greece. A little green lentil also does the trick; on the other hand, avoid Syrian coral lentils because they crumble during cooking. Lentils do not require pre-soaking; however, it is advisable to rinse them under cold water before cooking and sort them to remove any grit or impurities.
Option: add fresh spinach 5 minutes before the end of cooking. Season the soup with cumin or ground coriander. Sprinkle with chopped parsley or cilantro. Add a little lemon juice just before serving or serve with lemon wedges.