Grind the basil, pine nuts, garlic and salt in a pestle and mortar (don't worry if you don't have one, just pop all of your ingredients into a blender and give it a good mix)
Add 2 - 3 tbsp of extra virgin olive oil (if you want more of a chunky pesto don't add as much olive oil, if you prefer the saucier type add more - it really depends on what you like) and season to taste.
Add the nutritional yeast and stir gently, then add a dash of lemon juice for that perfect tangy twist, and drizzle with some more olive oil. It's sooo good!