According to the husband-and-wife duo at Blue Mountain Bistro in Kingston, a good cook is always on the lookout for “the best” of anything. Light as air while rich and velvety at the same time, their dreamy dark chocolate mousse qualifies in spades. The recipe uses only egg whites, not the yolks, which is important because tempering the yolks is usually the hardest step in most recipes. Of course, it also frees up the yolks for other uses. (At the Blue Mountain Bistro, the couple makes crème brûlée using only the yolks — a match made in heaven for economy-minded chefs.) Make this ahead of time and spoon into glasses or serve from the bowl with biscotti or simple butter cookies.
9 oz bittersweet chocolate, chopped (we use Callebaut)
1 3/4 cups heavy cream
1/4 cup liqueur, such as Kahlúa or dark rum
1/2 cup sugar
4 large egg whites, at room temperature
Pinch plain salt
Whipped cream and chocolate shavings, for garnish
Place chopped chocolate in a medium or large bowl and set over a double boiler on low heat. In a separate small saucepan over low heat, bring 1/2 cup of the cream just to a simmer, then pour it over the slightly melted chocolate and mix well, making sure to eliminate any lumps. Stir in your choice of liqueur. Let mixture cool a bit while you whip the remaining cream and egg whites. The chocolate mixture should be cool enough that the whipped cream does not melt when being mixed in but not so cool that the whipped cream cannot be thoroughly incorporated.
In a bowl, whip the remaining 1 1/4 cups heavy cream with half the sugar to fairly stiff peaks. In a separate bowl, whip egg whites with a teensy pinch of salt, adding the remaining sugar. Whip until the whites are fluffy, shiny, and full of air. This is what gives the “mousse” to the chocolate mousse.
Begin folding whipped cream into the cooled chocolate in thirds, that is, one-third at a time. The first batch should go in with your whisk. Mix well, trying not to lose the volume of the whipped cream. Easy does it. You should now be switching over to a rubber spatula as you gently fold in the second third, and then the final third of the cream, working from the outside as you turn the bowl around.
Next begin incorporating the beaten whites into the chocolate-cream mix, one-third at a time as with the whipped cream. The goal is to combine everything with as light a touch as possible and to eliminate any streaking, all without deflating the whites. Spoon into a serving bowl or individual dessert bowls or glasses. Cover and refrigerate for at least an hour or up to overnight.
Garnish with a bit more whipped cream and some extra shaved chocolate for a professional touch.