Roughly chop the spinach. Drop it in the food processor along with all the other ingredients except oil.
Lightly pulse until it's all mixed together.
Keep the food processor running and slowly add oil from the top.
Let it blend till the mixture becomes creamy.
If you are not using the pesto right away, store it in a air-tight jar. It can be refrigerated for about 2 weeks and if you wish to store it longer, you need to freeze it.