1 teaspoon instant coffee granules dissolved in 2 tablespoons boiling water
1/4 teaspoon kosher salt
Grated zest of 1 small orange (optional)
Chopped pistachios for serving (optional)
Instructions
Place the chocolate in a microwave-safe bowl and melt in a microwave, stirring after each 10-second increment, until smooth, about 1 1/2 minutes. Let cool slightly.
Place the egg yolks and 1/2 cup sugar in a medium bowl and whisk until pale yellow. Whisk in the olive oil, coffee, zest, if using, and salt until combined. Add the melted chocolate and whisk until smooth.
Beat the egg whites in the bowl of a stand mixer or with a hand mixer until soft peaks form. Gradually sprinkle in the remaining 1/4 cup sugar and beat just until stiff peaks form. Add a generous spoonful of the egg white mixture to the chocolate mixture. Stir firmly until completely incorporated. Pour the chocolate mixture into the bowl of egg whites. Gently fold with a large spoon or rubber spatula until completely combined.
Divide the mousse into six 6-ounce ramekins and cover with plastic wrap. Refrigerate for a few hours or overnight.
