remove the herbs from the sprigs and finely chop them. add them to a bowl.
repeat the chopping with the walnuts and the garlic gloves. if you like a really fine pesto, chop the nuts accordingly. i like them to be a bit coarse, it gives it a bit of texture. add the nuts to the herbs.
grate the parmesan cheese and add it to the bowl.
juice the lemon, add it to the mixture as well.
now you can add the olive oil and combine everything into a smooth paste. season it with salt and freshly ground pepper.