Asparagus peas - use them for edging flower borders as well as for their eating properties... grew them last year, eat the pods SMALL... if you forget, gather the bigger pods for snacking on... peel open the internal parchment, and snaffle the small green 'peas' inside at your leisure.
Not particularly prolific, and people's opinions on flavour/usability vary wildly, however I was rather taken with them, and will be sowing some later this week for border & snack attack availability.