Grate or chop the amount of chocolate you need. Place it in the top of a double-boiler or in a glass bowl that fits snugly over a small saucepan containing hot (not boiling) water.
Melt the chocolate slowly at 40–45°C (use a sugar thermometer), stirring with a silicone spatula.
TIP: If the chocolate gets too hot, or comes into contact with steam or water, it will seize or harden and you won’t be able to use it. If your chocolate does happen to seize (it’s happened to all of us), chop it up to use as an ice-cream topping or in chocolate chip cookies.