Moira Hodgson's Chocolate Mousse

Preparation

1. Step 1

   Heat the cream until small bubbles form around the edge.

2. Step 2

   Meanwhile, melt the chocolate in the upper container of a double boiler set over very hot water. Whisk in the egg yolks, one at a time, then whisk in the butter.

3. Step 3

   Gradually add the hot cream, whisking constantly. Turn up the heat so that the water in the bottom of the double boiler starts to simmer gently. Cook for four minutes, whisking constantly (the yolks are cooked at 160 degrees on a candy thermometer).

4. Step 4

   Remove the chocolate mixture from the heat and add the vanilla extract. Cool, stirring constantly for about five minutes.

5. Step 5

   Beat the egg whites until they stand up in glossy peaks. With a large rubber spatula, stir one-third of the egg whites into the chocolate mixture, then gradually fold in the rest.

6. Step 6

   Scrape the mousse into a large bowl or individual dishes. Cover with plastic wrap and chill until firm (about two hours for individual bowls and about five hours for a large mousse).