Melt the chocolate and coconut oil in 30 second intervals in the microwave until melted. Or you can do this over a double broiler.
When the nice cream balls are firmed up, dip them in the melted chocolate and set on parchment or wax paper.
Immediately sprinkle with flaky sea salt. If you wait too long, the chocolate shell may start to harden and the salt won't stick.
Pop them in the freezer until you're ready to enjoy.