Add all the nuts, garlic, salt and pepper to the bowl of a food processor. Pulse a few times, then add in the basil and lemon juice, pulse briefly.
With the food processor running, stream in the olive oil slowly until combined.
Add in the parmesan cheese and pulse just enough to combine. Add a little more olive oil if needed to make it loose enough to pour over zoodles.
This pesto freezes beautifully, so you can make a double batch and freeze some for later. Another great tip, pour some into ice cube trays and freeze. You can take out just what you need, when you need it! Note: Pine nuts are used in traditional pesto sauces, but I know they can be difficult to find in some areas. Walnuts are an excellent substitution in this case, and I definitely recommend toasting either nut you decide to use.