Fill a large bowl with water and ice cubes and set aside.
Fill a medium saucepan halfway full of water and bring water to a boil over high heat.
With water boiling, submerge herbs for no longer than 60 seconds.
Remove herbs from boiling water and submerge into bowl with ice water.
Once herbs have cooled completely, remove them from the bowl and dry them thoroughly.
Add herbs and olive oil to a blender and blend for approximately 60 seconds, stopping after 30 seconds to scrape down the sides of the blender.
Line a mesh strainer with a flour sack towel of cheesecloth and place it over a clean, dry bowl. Pour oil into the lined mesh strainer.
Transfer oil into a glass bottle with a tight-fitting cap. Refrigerate oil.
Oil will stay at peak freshness in the refrigerator for a few weeks. Or, if transferred to the freezer (in a freezer-proof container), the oil will stay at peak freshness for a few months.