1. Bring 1 inch of water to a simmer in a double boiler set over medium-high heat, then place chocolate in the top pan. (Alternatively, to improvise a double boiler, place chocolate in a heat-safe mixing bowl that fits snugly over a pan with 1 inch of simmering water.) Stir until half the chocolate has melted. Remove the bowl and continue stirring until the chocolate has fully melted. Cool for 5 minutes at room temperature.
2. Place the chocolate in a microwave-safe bowl and microwave on High for 1 minute. Stir well, then continue microwaving in 30-second increments on High until two-thirds of the chocolate has melted, stirring well after each heating. Remove the bowl and continue stirring until all the chocolate has melted. Cool for 5 minutes at room temperature.