1. In a small saucepan over medium heat, whisk together milk, heavy cream, powdered sugar and agar powder
2. Slice vanilla bean lengthwise, scape out seeds and add seeds and pod to the saucepan
3. Bring to a gentle boil while whisking (only small bubbles appearing on surface)
4. Turn off the heat, remove the vanilla bean and whisk in chocolate pieces. Let rest 1 minute, then stir again to make sure chocolate is incorporated
5. Add 2 egg yolks and whisk in thoroughly
6. Divide among 4 ramekins or molds and chill 20-30 minutes or until firm
7. Run a knife along inside of molds to loosen panna cotta and invert onto plates or serving bowl
8. Garnish with fresh berries, powdered sugar and/or chocolate sauce

Recipe adapted from "Cooking for Geeks" by Jeff Potter