- Toast the pine nuts in a dry skillet on medium heat until golden brown, about 5 minutes. 
- Place the lemon juice and garlic in the bowl of a food processor and blend. 
- Add the basil leaves in 2 - 3 lots, blending in between until finely chopped. 
- Add the pine nuts and cheese (if using) and process until well blended. 
- With the machine running, drizzle in the olive oil and process until smooth. 
- Add more olive oil to get your desired consistency. I find ¼ cup is never enough. I like it to be a thicker paste so I can thin it down with some pasta cooking water. 
- Taste for seasoning and add more salt if needed. 
- Mix through your cooked pasta with a splash of pasta cooking water. 
- Add some extra fresh basil, a squeeze of fresh lemon juice and some toasted pine nuts to serve.