Combine the basil, chives, parsley, parmesan, ½ cup oil, lemon juice, garlic and macadamias in a food processor. Season, then whiz to a paste. Transfer to an airtight container and refrigerate until ready to use.
Cook the pasta according to packet instructions.
Meanwhile, heat the remaining 2 tbsp oil in a large frypan over medium heat. Add the tomatoes, season and cook, stirring for 2-3 minutes until starting to soften. Add prawns and stir for 1 minute to warm through. Drain the pasta and add to the pan with all the pesto and gently toss to combine.
Serve pasta scattered with feta. (I also scattered with extra macadamia nuts)