Welcome to one of the perks of CSA membership. The garlic scape is the top of the garlic plant, sort of like a big chive, but with more garlic flavor. Scapes keep very well in the fridge. Chop them and saute them much like you would use garlic. I have cooked the whole thing slowly in olive oil and they become soft and mellow. You can throw a whole scape into pasta sauce or soup. Experiment and enjoy.