Keep a large bowl and beaters (of handheld mixer) in the freezer for 20-30 minutes to chill.
Melt Chocolate in the microwave and keep aside. If it starts to firm again, microwave for few seconds to melt it again.
Whip cream until stiff for approximately 4 minutes, first whipping at slow speed and then at high, taking care it doesn’t turn into butter.
In a small bowl whisk together coffee and sweetened condensed milk.
Add whipped cream little at a time to the coffee mixture and fold gently to mix it (do not mix vigorously).
Pour the ice cream mixture in a hollow container or loaf pan.
Drizzle the Chocolate and spread it with a toothpick or skewer to create the ripples.
Cover the pan with cling film (at least 2-3 films to prevent ice crystals from forming).
Freeze the ice cream overnight or at least for 6 hours. Check for ice crystals. If ice crystals form, then clean them out and cover the pan again with cling film.
Serve chilled.