On a piece of parchment, finely chop chocolate using a serrated knife; place in a large bowl.
Prepare an ice bath. In a small saucepan, bring heavy cream to a simmer. Remove from heat, and pour over chopped chocolate. Using a rubber spatula, gently stir until chocolate melts. Divide mixture between two heat-proof bowls. Set one aside. Set one bowl over ice bath, and stir until mixture reaches the consistency of toothpaste.