Cut the parmesan cheese and garlic into 1-inch chunks, then put them and the pine nuts into the food processor. Turn on until everything is in small pieces.
Add basil, salt, and pepper to the food processor and combine. When the mixture is roughly chopped, begin to drizzle olive oil in with the blade still running. This helps the oil distribute and create an even texture.
Add oil, pausing occasionally to check the texture. You want it to be pretty smooth and spreadable, similar to whole grain mustard in texture. Usually, I add about ¼ cup to get it looking how I want.
Store in small containers and put a layer of plastic wrap over the surface of the pesto in each. This helps slow down the oxidation process and keep that bright green color. Each batch makes about 12 ounces.