Grate the zest of the lemon then squeeze out the juice.
Tip these into a small blender, add the herbs & nuts, then pulse to a coarse paste. Season with salt and pepper, then slowly and gradually add enough olive oil to make a thick paste.
Wash the spinach, drain, then put in a mixing bowl.
Boil the pasta according to the instructions on the package. Pour cooling water over the spinach and leave for 2 minutes until it's wilted, then drain and squeeze out the water through a sieve.
Chop it up roughly and stir through the pasta together with the pesto and raisins (if used).
Serve warm.