What you'll need:
2 flat/side drawer runners ( or 3 if the panel is quite large). I got 2 stainless steel ones for $20 from a kitchen hardware shop.
A flat panel to fit the space next to your cupboard/pantry) - mine was the same size as the panel on my Ikea pantry.
A suitable space you can access to screw or bolt drawer runners for the panel
A spare set of hands
Oh yeah, this is my first instructable. Next one I'll try to make sure to take more photos of the actual working steps.
Edit: i think in hindsight this is more suited to being a slideshow, only I couldnt work out how to do that at the time!
Step 1: Attach runners
Inset the drawer runner from the front of the pantry, so the shiny steel doesnt poke out too obviously.
I didnt want to make a mess of my panel so I predrilled the holes, but if you are using self-tapping chipboard screws you can risk it. I wouldn't because I've learnt that lesson the hard way.
Also, be sure to measure your screws so they don't poke through to the inside of the pantry. Seems obvious, but the way I forget things, a little reminder never hurts.
P.s. best to do this before you put up the next cabinet... if you do it after, i guess you could put your runners in from inside the pantry but it's a lot more fiddly.