Pulse the basil, pine nuts, cheese, and garlic together in a food processor or blender. Scrape down the sides, then add the oil, lemon juice, and salt. Pulse until everything is blended together and relatively smooth. Add a drizzle more olive oil to thin out, if desired. Taste and add pepper (and/or more salt) if desired. I always add a pinch of pepper.
Store pesto in a jar or sealable container, tightly seal, and refrigerate for up to 1 week.