Wild garlic.

There's miles of it along the streambanks around here. I've been collecting bagfuls of it on walks and stuffing every spare space in the freezers with it. Use like spring onion or leek, for cooking or raw in salads. I've planted some in the garden but for some reason it prefers to grow near running water, which we aren't - who knows, we might get lucky. We already have a fair bit of self-seeded sorrel, so we're doing ok for fresh greens.