Berry Gratin With Champagne Sabayon

The sauce of the easy appetizers you need is based on a foamy mixture called a sabayon (a cousin of the light, egg-based Italian dessert zabaglione). A sabayon is made by beating egg yolks with a liquid over simmering water until thickened and increased in volume. ( the liquid can be water, but champagne or wine pairing is often used for a savory sabayon.) The sabayon must not get too hot during cooking or it will become grainy: if it begins to feel warmer than body temperature, remove the pan briefly from the heat, beating continuously, until the mixture cools. Then return the pan to the heat and continue cooking. Sabayon may be served warm or cold; a cold sabayon is beaten off the heat until cooled.

Sabayons may be sweet or savory. They may be served simply as a sauce, often flavored with an alcohol, or they may form the base of some mousse mixtures. They may also be used for sweet or savoury gratins. Cornflour is sometimes added for stability.

Ingredients:

4 handfuls mixed berries
3 egg yolks
2 tablespoons caster sugar
3 tablespoons sparkling wine
Zest of half a lemon


Methods:

1. Turn the oven on to grill with the rack about 6 inches/15 cm from the heat.
2. Arrange the berries in individual gratin dishes and set on a baking sheet.
3. Prepare the Sabayon: Put the egg yolks, sugar, and wine into a roomy glass bowl.
4. Whisk to mix.
5. Set the bowl over a saucepan partly-filled with hot, but not simmering, water.
6. Don't let the bottom of the bowl touch the water beneath.
7. Whisk until the mixture is frothy, pale, and ribbony, 5 to 8 minutes.
8. Remove from the water.
9. Whisk in the zest and keep whisking a minute or two to cool slightly.
10. Spoon the sabayon over the berries and place under the grill until the sabayon is bubbly and golden, a minute or two.
11. Transfer to plates and serve immediately.