Preheat oven to 325°F 

In a small saucepan combine the milk and cream. Whisk in the espresso powder until fully combined.  Bring to a low boil over medium-low heat, stirring frequently.  Small bubbles will start to form at the edges of the pan.  

While the milk mixture is cooking, whisk the eggs and sugar together in a small bowl. 

Remove the pan from the heat and add the chocolate.  Whisk until smooth and the chocolate is completely melted.  

Add a small amount of the chocolate mixture to the eggs.  Whisk until combined.  Add the egg mixture to the remaining chocolate mixture in the pan.  Whisk well.  

Divide the mixture between 3 or 4 oven-safe ramekins.  Place the ramekins on a rimmed baking dish and fill the baking dish with very warm water until the water reaches about halfway up the sides of the ramekins.  Be careful not to splash water into the chocolate.  

Carefully place the baking dish in the oven and bake for 30 minutes or until the custard is set but still slightly jiggly in the middle.  Remove from oven and let cool for 5 minutes.  

Refrigerate the custards for at least three hours before serving.  Top with whipped cream, shaved chocolate and sea salt to serve.