tbsp of the Parmensan cheese, stock and lemon juice until smooth. Pour over pasta. Sprinkle with pine nuts and remaining Parmensan cheese. Toss. tips: Even with lemon juice the pesto may discolour, if this happens, skim off the darkened surface and discard. Toast pine nuts in a skillet on stove top for 2 to 3 minutes until brown. This is like a guacamole dressing with much less fat due to the basil and parsley. For a stronger flavor use all basil and no parsley.