Place all the ingredients in the food processor except the oil. Pulse to combine and chop the ingredients, about 6-10 pulses.
Turn the processor on high and slowly drizzle in the oil through the feed tube until you reach your desired consistency. Personally, I prefer to keep mine on the thick side and thin it down at a later time, depending on what dish I'm preparing.
Scrape the pesto into an airtight container.
To keep the pesto fresh and preserve the bright color, cover the exposed top of the pesto with oil to create a “seal.”
All of these have the same method to put together. Using a food processor makes easy work, but you can also use a mortar and pestle.
Pesto stores beautifully in the freezer for 3 months or in the refrigerator for 3 weeks.