Wash and trim the broccoli rabe. Discard the tough stems and roughly chop.

Place the broccoli rabe and basil leaves in the bowl of a food processor. Add the cheese, lemon zest and lemon juice. Pulse until contents are finely chopped and blended.

While the machine is running, add the olive oil in a slow steady stream. Continue to pulse until desired consistency is achieved.

Give it a taste and add salt & pepper as needed. If using red pepper flakes, add the desired amount. Pulse again to blend.

Prepared pesto will keep well in the fridge for up to a week.