In reply to Flinticus:
For something smaller to break you in more gently, there's loads of good walking in the Pentlands, with a variety of good paths and off-path wandering to be had.
The Shee of Ardtalnaig south of Loch Tay is a bonny walk, with good paths.
Then you could work up to some of the Corbetts south of Loch Tay, or the Rob Roy Way, or walk up Kirkton Gln to the wee lochan, which I find a bonny walk.
After this, I would not go on to Ben Ledi straight away as there are some steepish bits. I'd suggest Ben Chonzie as the next step up. Then perhaps a trip up to Glenshee. Glas Tulaichean is a remote-feeling hill, but has a good track all the way to the top.
Hopefully this would see your ankle back to proper strength