One of the best things about the local farmer's market is being able to get baggies of fresh basil cheaply and easily. And the best thing about big bags of basil is PESTO! There are so many ways to make pesto, many of which don't even call for basil but for some other green, leafy thing. Spinach, parsley, you name it. Some with nuts, some with cheese, some with both. So, this is only one simple way to make pesto and the high quantity of nuts and tomato make this a fairly dull-looking sauce. I have to say though, it's definitely tasty. I like to make a concentrated paste that's easy to store then mix it up with enough water to thin it to my desired consistency. Pasta water works great because of its high starch content.
Combine everything in the bowl of a food processor. Process until a thick paste forms, adding just enough water to enable the processor to efficiently work. Store in the fridge until needed.
To use: Mix with sufficient water to make a sauce to your taste.