Place the broken chocolate in a heatproof bowl. Melt the chocolate in the oven on a very low heat (75–100°C/Gas ¼). It should melt in about 5 minutes – keep checking it with a fork. When melted, take out of the oven and beat with the butter in a large bowl until smooth and light.
Using an electric beater, whisk the egg whites until frothy. Add
Stir half the egg mixture into the chocolate and butter mix. Fold in the remaining egg with a large wooden spoon, working in from the outside, slowly and calmly. You need not worry about the mousse setting while you work, because the butter keeps it soft.
Pour into a large soufflé dish or 8 individual ramekins and refrigerate until set, about 2 hours or overnight.
© 2003 Chantal Coady. All rights reserved.