1. Heat the olive oil in a saucepan.
2. Add the chopped onion, carrot and celery and stir them in the oil.
3. Put the lid on a cook over a medium to low heat for about 5 minutes.
4. Then stir in the lentils, garlic and herbs.
5. Barely cover with water.
6. Bring it to the boil, then lower the heat and cook over a low heat for about 20 minutes.
7. When it is cooked, add the grated cheese and serve.
Can be frozen for up to 4 weeks.