Strawberry Knotweed Pie!
It's early invasive plant season, which means it's time to harvest Polygonum cuspidatum, aka Japanese knotweed, to make yummy pie! Japanese knotweed wreaks havoc on the environment but makes for yummy food, such as Strawberry Knotweed Cobbler. I first discovered knotweed's yumminess on an edible wilds hike with Russel Cohen, and now go out of my way to harvest the tender shoots in spring. Sauteed it's very similar to asparagus (and not six dollars an organic pound).
I swear, Japanese Knotweed makes a superior substitute for rhubarb in pie -- it seems to cook down with less mucus and in less time. And, well, yeah, if you harvest it, you are helping the environment -- but don't let the do-good stop you from trying out the yum!
A note on harvesting edible wilds: I don't harvest wilds along roads because of the pollution/contamination problems, but, if you live near Davis Square, Somerville, MA, for example, there are several "healthy" stands of Japanese Knotweed along the bike path. If you're interested, I'll even show you where they are -- no pie fee required. :)