Meanwhile, add all ingredients for the pesto to a blender and whizz until smooth (you may have to mix it around a few times to ensure it's all evenly blended, and add a splash of water if necessary)
Put the cornflour in a bowl and dissolve in a splash of cold water
Heat up a frying pan and add the milk and pesto
Once (and only once) the sauce is very hot and bubbling, stir in the dissolved cornflour
Drain the pasta once cooked and add to the pan with the sauce. Mix well
Transfer onto plates and top with a handful of rocket to serve