Heat on medium until the water begins to simmer. Turn down the heat to low.
Add the chocolate to a heatproof bowl that fits on top of the saucepan without touching the water.
Place the bowl on the saucepan.
Use a whisk or silicone spatula to stir the chocolate frequently.
Remove the bowl from the heat once the chocolate is roughly 98% melted.
Stir until the chocolate is fully melted.
Notes
You can use this method for varying amounts of chocolate. It works best with chocolate bars and wafer, but you can also use it for chocolate chips.Be careful to not introduce water or steam into the chocolate as it melts, otherwise it may seize.