Pumpkin seeds are much cheaper than pine nuts, and seem to be OK for people with nut allergies too.
100g pumpkin seeds
100ml olive oil
4 cloves garlic
juice of 1 lemon
About 15 stems of basil
Roast the pumpkin seeds in a pan, stirring occasionally until they pop and go brown around the edges.
Grate the parmesan
Put the basil into the liquidiser. Put everything else in on top of the basil.
Turn it on quite briefly until you have a sort of lumpy paste (The second time I made this, I put the pumpkin seeds at the bottom, so they got ground too small by the time the basil had hit the blades. Putting the basil in first and the seeds last should prevent this).
And now I really can say: Hey Pesto!