Fill a large pot with water
Place a heat-safe bowl inside the pot so it floats above the water level
Put a lid on the pot upside down
Heat the water until it simmers
Place ice on top of the inverted lid
Let the steam rise, condense on the lid, and drip into the bowl
Turn off the heat when enough distilled water has collected
Let everything cool before removing the bowl
Pour the collected water into a clean container