Espagnole Sauce
‘This is one of the classic ‘French sauces, and very important to both ‘English and Trench chefs.

1 oz (25g) butter           
4oz (100g) carrot, finely diced
1 oz (25g) flour           
4oz (100g) onion, finely diced
1 tablespoon tomato purée           
2oz (50g) celery, finely diced
1 3/4 pints (1 litre) beef stock           
2oz (50g) leeks, finely diced
2 tablespoons wine vinegar           
2oz (50g) fennel, finely diced
A little oil or butter           
A sprig of thyme
Salt and freshly ground black pepper           
1 small bay leaf
4oz (100g) rindless smoked bacon, finely diced

1. Heat the butter in a heavy-based saucepan and stir in the flour to make a roux. Do not let the mixture burn. Add the tomato purée to the roux, then slowly add the hot stock and the vinegar.

2. In a separate saucepan, heat the oil or butter and cook the bacon and vegetables until light golden. Drain the vegetables, add them to the sauce with the herbs and seasoning and simmer slowly for at least 4 hours.

3 Skim with a ladle, strain through a fine sieve into a clean pan, and reheat when needed.