Heat the oven to 180°C (350°F) Gas 4. Brush the insides of four 150 ml (1/4 pint) souffle dishes with butter, then stand them on a baking sheet.

Melt the margarine in a fairly large saucepan, sprinkle in the flour and stir over low heat for 1 - 2 minutes until straw-coloured. Remove from the heat and gradually stir in the milk. Return to the heat and simmer, stirring, until very thick and smooth.

Remove from the heat, allow to cool for a few minutes, then beat in the egg yolks one at a time. Stir in the caster sugar and coffee essence.

In a clean, dry bowl, whisk the egg whites until they stand in stiff peaks. Using a large metal spoon, lightly but thoroughly fold egg whites into the coffee mixture. [J]

Spoon into dishes. Mark a circle with a knife in the top of each souffle. Bake in the oven, above centre, for 25-30 minutes until risen well above the rims of the dishes and browned on top.

Meanwhile, make the sauce: pour the hot coffee into a small pan and then stir in 1 1/2 tablespoons sugar. Blend the arrowroot with the water, add to the sweetened coffee and simmer gently, stirring, until thickened and no longer cloudy. Remove from the heat and flavour with Tia Maria and more sugar, if liked. Keep hot. Serve the souffle's immediately they are cooked, with a little of the sauce poured over them and the rest handed around separately in a jug.