Wild garlic
Smells like garlic, looks like a broad leaf. When in doubt, smell it.
Allium ursinum — if it smells, it's safe
Wild garlic carpets woodland floors in spring, and the smell gives it away before you see it. Crush a leaf — if it doesn't smell of garlic, it isn't wild garlic.
How to pick
season march–may, before it flowers look for broad, soft, glossy leaves the test crush and smell — garlic = yes, nothing = no careful don't confuse with lily of the valley
What to do with it
Pesto is the classic, but the leaves also wilt into butter, eggs, or anything that likes garlic. The flowers are edible too.