Chop chocolate into small pieces and place in the bowl of a food processor. Process until finely chopped, and transfer to a microwave-safe bowl, reserving about 1/4 cup of the chopped chocolate.

Microwave in 30-second intervals, stirring with a spatula, until 2/3 of the chocolate is melted.

Use the spatula to stir and fold chocolate until it's smooth.

Test for temper by spreading a small amount of the chocolate on a piece of parchment. If it hardens nicely, the chocolate is ready; if not, stir in about 1/2 of the reserved chopped chocolate and test again.