I'm vaguely remember hearing about this from a couple of different sources - I think the basic idea is that you generate lactate doing a 200 or 400 at 800m pace or faster, then follow it up with a mile at tempo/lactate threshold pace (~85% vvo2max).
Not sure what the rests are - I think it's a shorter rest than normal after the faster interval (1-3min), and a longer than usual rest after the tempo/threshold interval (>1min).
Other versions I've heard about include 6 x 200 at 800m race pace, followed up by 4-6 x 800 at 3200m race pace.