Once that is done remove from the steamer and let sit for a few minutes to drain.
Put the steamed nettle into the food processor and add all the other ingredients except the olive oil. Turn on the machine and process then slowly add the olive oil in a small stream into the ingredients until used up.
You should have a nice smooth sauce when done.
Mix over your favourite hot pasta and add a little more cheese if desired.
Enjoy with a glass of chilled wine and garlic bread.