Step 1

Prepare 2 mixing bowls: one large and one medium bowl. The medium bowl needs to be able to nest inside the large bowl. Add ice to the bottom of the larger bowl and then put the medium bowl inside. There should be enough ice to cool the bottom and sides of the medium bowl.

Step 2

Add chocolate and water into a medium saucepan and bring to medium heat. As the water heats up, whisk until you have a uniform melted chocolate mixture. This should only take a minute or less once the water is hot. After the chocolate is melted and uniform, remove the saucepan from the stove.

Step 3

Pour the melted chocolate mixture into the medium bowl. Make sure to use a spatula to scrape all the chocolate from the saucepan into the bowl. Working quickly, whisk vigorously as the chocolate begins to cool down, until the mixture thickens to a pudding consistency. You can either use a hand whisk or a hand mixer using the whisk attachment on the lowest speed. It will take about 5 minutes or slightly longer to reach the right texture. The mixture is going to thicken and stiffen even more once you stop mixing so you want the mixture to be just a little less stiff than mousse consistency since it will thicken more once you stop mixing. If your mixture can hold soft peaks, you've likely overmixed it. See notes on how to fix your mousse if this happens.

Step 4

Stop mixing once mixture reaches pudding consistency. Scoop mousse into small dessert bowls or into a piping bag and pipe into bowls. The mousse will set within a few minutes after you stop whipping it. If desired, top with fresh whipped cream and shaved chocolate curls.