Fill just the bottom of a pot with water. Place a Pyrex dish on top (I use a wooden spoon to allow steam to escape). Add the 4 ounces of unsweetened chocolate into the Pyrex bowl and bring the pot of water to a boil. Make sure the boiling water does not touch the Pyrex dish. The steam from the boiling water will melt the chocolate in the Pyrex dish. Once the chocolate is completely melted, allow it to cool a few minutes. Some people microwave the chocolate… I don’t use microwaves for personal reasons, but that would be another way to melt the chocolate.