Whisk egg and egg yolk together in a small bowl. Set aside.
Add milk and cream together in a heavy saucepan. Bring just to a boil and remove from heat. Stir in chopped chocolate (or chocolate chips) and vanilla extract, and let sit, untouched, for several minutes to let the chocolate melt. Once melted, whisk the mixture until smooth.
Add 1/3 cup of the chocolate mixture into the eggs and stir until well combined. Now, add all of this back into the remaining chocolate mixture in the pan. Whisk until thoroughly combined.
Pour the filling into the prepared crust and bake for about 30 minutes, or until mostly set, but still a tiny bit jiggly in the center. Remove from oven and cool completely on a rack. The center will set up as it cools. Once completely cooled, garnish edges with chocolate shavings and the center with edible flowers. Refrigerate. Bring to room temp for about 15-20 minutes before serving. Serve plain, or with a dollop of whipped cream