Ingredients

2 good sized onions
2 cloves garlic
1 medium celeriac
1 tablespoon olive oil
a knob of butter
1 litre/ 1 3/4 pt light stock (vegetable, chicken or even turkey!)
a sprig of rosemary
1 teaspoon dried sage
salt, pepper

Method

Peel and finely chop the onions, garlic and celeriac. (You can grate them in a food processor if you want to speed things up).

Place the oil and butter in a large heavy pan over a low heat. When the butter has melted, add the prepared vegetables. Stir around, cover and cook slowly until browning. Add the stock and herbs. Simmer for around 20 minutes. Check seasonings. If you like a clear soup, strain into a jug and then pour into your Thermos Flask.