Toast your pine nuts in the oven for 15 minutes on 400°F, gas mark 6, 200°C (180°C fan-assisted) laid out on a baking tray in a single layer. Bake for 10-15 minutes, stirring every 3-5 minutes, or until golden brown, then immediately transfer to a plate to stop the hot tray from continuing to cook them. Alternatively place the pine nuts in a dry (don’t add oil) frying pan large enough to hold them in a single layer, and cook until fragrant and golden brown keep them moving (stir frequently or constantly) for about 3-5 minutes, when they are golden brown transfer to a plate to stop the cooking process and leave to cool. Top tip – do not take your eye off them even for 1 minute!
Place the basil leaves, into a food processor and blend roughly chopped. Add the toasted pine nuts and 10 tbsp. of olive oil, sea salt and the nutritional yeast flakes, blend all together, scrapping down the sides of the food processor.
When you’ve reached a smooth yet coarse texture, place the mixture into a mixing bowl and stir in 5 tbsp. olive oil, then place the pesto into a Kilner jar.
The pesto sauce will keep fresh in the refrigerator for 7-10 days, alternatively you can freeze in mini ice cubes for up to 3-6 months.