Step 1

Bring a large kettle of salted water to a boil. Blanch herbs by plunging into the boiling water for about a minute. They should be wilted and tender, but not limp. Immediately transfer to a colander and rinse with cold water.

Step 2

Pat herbs dry on a clean towel. Chop roughly and place in blender with oil.

Step 3

Blend until smooth, about 3 to 5 minutes, then transfer to a non-reactive container. Cover and let steep for several hours, preferably overnight.

Step 4

Line a funnel with butter muslin and place in a small jar to keep upright. Fill with herb and oil slurry and let drain for several hours. Do not squeeze out oil.