In a blender, puree the herbs and oil until completely smooth. Put the mixture in a saucepan and bring it to a simmer over moderate heat. Simmer for 45 seconds, then pour through a fine-mesh strainer into a bowl. Don?t press on the mixture, but you can tap the strainer against your hand to get the oil to drip through faster.

Immediately strain the oil again through a flat-bottomed paper filter. If the filter clogs, you may need to change the filter partway through. It's okay to pick the filter up and squeeze it gently to get the oil out faster, but be careful not to break the filter.

Sometimes a little dark liquid comes through the filter first. Don't worry; that's water. It will settle to the bottom because it is heavier than the oil. Let the filtered oil settle for a few hours, then pour it off the dark liquid. Store in an airtight jar in a cool, dark place.