Preheat the oven to 300˚F. Draw an 8-inch circle on parchment paper. Invert the paper onto a baking sheet.
Beat the egg whites with a pinch of salt on medium-high speed until soft peaks form. Slowly add ¾ cup sugar and beat on high until the whites are shiny and stiff (they should hold a point when you lift the beater). Add 1 teaspoon of the vanilla along with the bourbon, and beat until just combined. Using a spatula, fold in the chocolate. Scrape the meringue onto the parchment, and spread it into an 8-inch round, using the circle as a guide.
Bake the meringue for 60-70 minutes, or until the surface is dry (it might be lightly cracked). Transfer to a cooling rack (on the baking sheet) and let cool completely. Carefully peel off the parchment paper before serving. Do Ahead: The meringue can sit at room temperature, uncovered, for up to 8 hours.
Beat the heavy cream with the remaining 1 teaspoon of vanilla and the remaining 1 teaspoon of sugar until soft peaks form. Do Ahead: The whipped cream can be covered and refrigerated for up to 4 hours. Beat lightly with a whisk before serving.
Assemble the pavlova right before serving. Spread the whipped cream over the top of the meringue. Arrange the strawberry slices in concentric circles around the whipped cream. Shave a good amount of dark chocolate over the whole thing. Serve immediately.