Melt couverture over bain-marie.
Disolve instant coffee powder in 1 tsp of hot water.
Whisk cream until stiff.
Mix melted couverture, sweetened condensed milk, disolved coffee and salt in a bowl.
Fold in whisked cream.
Pour in a closeable box.
Place in freezer for minimum 5 hours.
I use an empty 900 ml ice cream box.