Petits pots de crème au chocolat

1.Bring cream, milk and vanilla seeds to the simmer in a saucepan over medium-high heat. Meanwhile, whisk yolks and sugar in a bowl until pale. Add cream mixture and whisk to combine. Return to pan and stir continuously over medium heat until mixture coats a spoon thickly (4-5 minutes). Remove from heat, add chocolate, whisk until smooth and combined, then divide among six 150ml serving jars or glasses. Refrigerate until completely chilled and set (3 hours). Serve topped with a dollop of créme fraîche, dusted with cocoa, with biscuits for dipping.