Instant custard is all very well, but nothing beats a proper crème anglaise, especially when it’s perfumed with lemongrass. These cups make a fantastically elegant dessert, which can be made well in advance and finished off with a dusting of sugar and blast of a chef’s blowtorch.
Combine the cream and milk with the lemongrass in a large saucepan and scald the mixture, pressing down on the lemongrass in the liquid to extract as much flavor as possible. Allow to cool and infuse for at least 1 hour, or cover and refrigerate overnight. Strain to remove the stalks. Return the mixture to the pan.
Beat the egg yolks in a large heatproof bowl set on a damp cloth to hold it steady. Scald the creamy milk again and when it is at the point of boiling, whisk it into the yolks in “slurps,” beating well.
Preheat the oven to 300°F.
Return the mixture to the pan again, pouring through a fine sieve. Beat in the sugar. On very low heat, stir the liquid with a wooden spoon until it starts to coat the back of the spoon, about 15 minutes. Remove from the heat, immediately strain again, and pour into four 4-ounce ramekins or heatproof cups.
Place the ramekins in a roasting pan or high-sided ovenproof dish, pour in enough hot water to reach halfway up the sides of the ramekins, and bake for about 45 minutes until the mixture becomes slightly set. Remove, cool, and chill until firm, at least 2 hours or overnight.
When you are ready to serve, sprinkle the ramekins evenly with brown sugar and caramelize it with a kitchen torch or under a hot broiler.
HOW TO PREVENT THE CUSTARD FROM SPLITTING
Beating in the sugar after the eggs helps to stabilize the mixture and means it will thicken more quickly.