A good stock is essential for a brown sauce. Bring 900 ml (1½ pints) beef or veal stock to the boil and simmer until slightly reduced to concentrate the flavour. This recipe makes about 600 ml (1 pint). Freeze any extra you don’t want.

1. Melt 25 g (1 oz) butter in a heavy-based saucepan and stir in 25 g (1 oz) plain flour. Cook the roux for 3–4 minutes over a medium heat until it is well-browned, stirring constantly so as not to burn the roux.

   

2. Off the heat, gradually stir in the slightly reduced hot stock and 1½ tablespoons tomato purée. Return the pan to the heat and bring to the boil, then simmer for 20–30 minutes, uncovered, skimming occasionally. Season.