1 cup heavy cream, chilled and divided
3 egg yolks
a cup of espresso or strong coffee at room temperature (not very hot)
3.5 tablespoons sugar
2/9 teaspoon of kosher salt 4 bars of chocolate (60-72% cacao), (chop them)
2 egg whites
1. Whisk 1/2 cup cream in a vessel until stiff peaks are formed. Cover the vessel and place it in the refrigerator for some time.
2. Mix the egg yolks, espresso, salt, and 2 Tablespoons of sugar in a large vessel. Set the vessel in a double boiler. Continuously whisk it until the mixture becomes lighter in colour and becomes double in volume. Cook the mixture for a minute until an instant thermometer inserted in the vessel reads 160 degrees.
3. Remove the vessel from the double boiler setup. Add some chocolate to it and whisk it continuously until it melts and smoothens.
Let it cool to room temperature.
4. Use an electric mixer to beat the egg white until it becomes foamy. Add 1 teaspoon of sugar to the mixer and beat continuously until firm peaks are formed.
5. Fold egg whites and chocolate together with whipped cream.
Distribute the mousse into 6 cups. Place them in a refrigerator and let them chill for some time. serve chilled