Preheat oven to 325 degrees.
Place the chocolate in a blender and pour the hot coffee over it.
Blend for a few seconds only.
Add the milk, sugar, salt and eggs; blend well but do not overwork.
Pour the custard mixture into individual custard dishes.
Place the dishes on a rack in a baking pan with an inch of hot, but not boiling, water.
Bake about 20 - 30 minutes.
Insert a knife near the edge of the cup.
If the blade comes out clean, the custard will be solid all the way through when cooled.
Cool for a few minutes on a rack, then refrigerate until ready to be served.