Pesto = toasted pine nuts (almonds are a good sub); Parmesan (any good hard cheese could work); oil (I used half olive half sunflower); just the smallest piece of raw garlic; nettle leaves (tops of the plants blanched for 45 sec in boiling water and then shocked in cold water, dried well, and then the leaves picked from the stems); salt; and pepper. Puree in a food processor or blender.
The pasta was Rustichella d'Abruzzo Farro Spaghetti procured at the Market at the Fig. The farro pasta worked well--I wouldn't love it in a simple tomato sauce, but here I liked it more than the refined alternative.
Anyway, if you're into this I'd try this as soon as possible. While the nettles will be around for a while, they won't be as good as they are now for long.