To make the creme anglaise:

1. In a petite saucepan, combine the half-and-half, vanilla bean, and mint. Bring just barely to a boil over medium heat, then pour into a bowl and cover with plastic wrap. Let the vanilla bean and mint infuse the cream for 20 minutes. Strain the cream and keep it warm.
2. In a medium bowl, whisk the egg yolks and granulated sugar. Gradually whisk 1/4 cup of the warm cream into the egg yolks. Slowly whisk in the remaining cream mixture. Return the cream to the French oven and cook over medium-low heat until the creme anglaise is thick enough to coat the back of a wooden spoon. Strain into a bowl, cover it with plastic wrap, and chill until ready to serve.

To make the souffle:

1. Preheat the oven to 350 degrees. Butter the sides of 6-6 ounces ramekins or cocottes. Sprinkle each pot with sugar, coating the sides and the bottom. Discard any excess sugar.
2. In a large bowl, combine the chocolate and warm cream. Let sit for 2 to 3 minutes, then whisk until smooth. Add 1/4 cup of the granulated sugar. the vanilla extract, and salt and mix well. Add the egg yolks and whisk to combine. Set aside.
3. In the bowl of a stand mixer, combine the egg whites and cream of tartar and mix on low speed until small bubbles begin to form. Increase the speed to high and mix until soft peaks form. Sprinkle in the remaining 1/4 cup granulated sugar, a small amount at a time, and continue to beat on high speed until smooth and flossy stiff peaks form. 
4. Using a spatula, fold 14 of the egg white mixture into the chocolate mixture. Add the remaining egg whites, being careful not to overtax. Pour the mixture into the prepared French oven and bake for 23-27 minutes, until the souffle has risen and the top appears set. Sprinkle with powdered sugar and serve immediately with the creme anglaise.