How to make a double boiler: Use a larger pot for the bottom boiler, and a smaller pot or heat safe glass for the top boiler. Make sure the top boiler is small enough to fit in the bottom boiler, but large enough to be suspended at least 2 inches from the bottom of it. Add 2 inches of water to the bottom boiler/pot, bring to a boil, then reduce to a simmer and add the top boiler/pot along with the chocolate chips and tablespoon coconut oil.