1. Peel and chop the onion and garlic.
2. Peel and chop the potato, carrots and celery into small pieces.
3. Heat the oil in a large saucepan and gently fry the onion and garlic for a few minutes.
4. Add the potato, carrots, celery and lentils.
5. Crumble in the vegetable stock cube and add 1 litre (1 ¾ pints) of boiling water.
6. Add the tinned tomatoes and season with black pepper and dried herbs.
7. Bring to the boil and then simmer for 20-25 minutes until vegetables are tender, stirring occasionally.
8. Serve as it is or blend with a hand blender/liquidiser until smooth.
2 cloves garlic
1 medium sweet potato
2 large carrots
3 sticks of celery
2 teaspoons vegetable oil
2 handfuls red lentils
1 vegetable stock cube
1 litre (1 ¾ pints) boiling water
1 small can chopped tomatoes
Ground black pepper
1 teaspoon dried mixed herbs