Bittercress (Cardimine hirsuta)

This plant is memorable, not. least because, when I was able bodied I would often pick this, before it flowered, to go in my egg mayonnaise sandwich. Made at home naturally. I would not entertain buying one of those sulphurous over cooked things from a shop or garage, yuk. 
Any hoo, Bittercress, much like it's cousin Mustard cress and a suitable replacement, through late winter and early spring.
In my defence, I am a chef, fussy. I would make my own mayonnaise as well.