Walky Leeks / Walking Onions

 
Sowed 15 Walky Leek bulbs (Purchased from *bay)

Never heard of Walky leeks before and there only seems to be that Ebay seller that calls them that so its probably a made up name. 
If you leave a leek to bolt and set seed there will be small bulbs at the base of the leek. Maybe this is what he's selling? Dunno but let us know how they grow for you.

Yes, Vinny, that's the one I saw. Found a reference to Multiplier leeks on an Australian Permies site but not much else.
Unfortunately, the Beechgrove garden episode isn't available now. https://www.bbc.co.uk/programmes/b0bkydb4

EDIT Found it on youtube but I can't see those leeks https://www.dailymotion.com/video/x74tetg

I'm still in the dark about whatever you've bought. I see that the Ebay Vendor is also intending to grow Walking Garlic............!!
He sounds like the James Wrong of Aberdeen to me!!

There's a good article about Walking Onions at https://www.egyptianwalkingonion.com/ but I've no idea how to answer your question about when to put them outside. What do you do with your ordinary onion and leeks?