Combine the cream, milk, sugar, coffee, and salt in a medium, heavy saucepan and heat over medium heat. Bring to a gentle boil and then remove pan from the heat.
Beat the egg yolks in a medium bowl. Whisk 1 cup of the hot cream into the egg yolks. Gradually add the egg mixture in a slow, steady stream, back into the hot cream.
Cook over medium-low heat, stirring occasionally, until the mixture thickens enough to coat the back of a spoon, about 3-5 minutes.
Remove from the heat and strain through a fine mesh strainer into a clean container. Cover with plastic wrap, pressing down against the surface to keep a skin from forming. Chill in the refrigerator for 4 hours or up to overnight. Place a vessel to store the ice cream in the freezer to chill.
Remove the mixture from the refrigerator and pour into the bowl of an ice cream machine. Churn according manufacturer instructions. Place the finished ice cream in the pre-chilled vessel and store in the freezer. When ready to serve, sprinkle a touch of the Fleur de Sel Sea Salt on top of individual servings, if desired.