How to make English custard

This pouring custard, crème anglaise, in French cooking make a deliciously light alternative to whipped cream for serving with ice cream, fruit-based desserts and other cream or moulds. If you are worried about curdling the custard, add the corn flour as safeguard.
Ingredients
Make about 600 ml/ pt
425 ml/15 floor oz milk
5 cm/2 in piece of vanilla pod, split, or 2.5 ml vanilla essence
45-60 ml/3-4 tablespoon caster sugar
5 ml/1 tsp corn flour (optional)
5 large egg yolks.
Preparation method
1) pour the milk into the top pan a double boiler, add the split vanilla pod, if using, and scald it over a gentle, direct heat that is bring it to just below boiling point. Remove the pan from the heat. If you are using a vanilla pod, cover the pan and leave to infuse for 10-15 minutes.
2) Place the caster sugar in a large bowl and mix in the corn flour, if using. Add the egg yolks. Whisk the ingredients together until pale and creamy, and so thick that mixtures falling from the lifted beaters leave a trail on the rest of the mixture. Add the hot milk in thin stream, whisking continuously.
3) bring the water in the bottom pan of the double boiler to the boil, then reduce the heat so that the water is simmering.
4) Return the egg mixture to the top pan of the boiler. Cook over simmering water for about 10 minutes, stirring continuously with a thick wooden spoon, until the custard is thick enough to a coat the back of the spoon. Test by drawing a finger across the coated spoon: it should leave a trail. Do not let the custard get so hot that the eggs curdle.
5) As soon as the custard thickened sufficiently, remove it from the heat and plunge the base of the top pan into cold water to prevent further cooking. Continue stirring for 1-2 minutes while the custard cools slightly.
6) Strain the custard through a fine sieve into a bowl. Serve the custard hot, warm or cold, favoring it with vanilla essence, if using, just before serving. If the custard is to be used hot, either serve it immediately or cover it and keep it hot over warm water for up to 30 minutes. Otherwise, cool the custard in a narrow necked jug, stirring frequently to prevent a skin from forming. Then cover the surface with a piece of lightly buttered grease proof paper, buttered side down, and chill until needed.
A classic English custard is flavored with vanilla, but liqueur may be used instead (adding it just before serving). For coffee custard, stir instant coffee granules into the custard before straining. On the other hand, for chocolate custard, reduce the caster the caster sugar to 25 g/1 oz and add 50 g/2 oz grated plain chocolate to the custard before straining.
Preparation time
30 minutes plus optional cooling and chilling.