Just had a delicious bread

At Bread Street Kitchen by Gordon Ramsay.  I'd love to know how to approximate it at home.  It was a artisan-style boule, the crust was moderately thick and crunchy, the crumb was tight (no big holes at all) and a medium brown, but incredibly light and fluffy, similar to tangzhong breads, the slices although about 1cm thick, were almost falling apart under their own weight.  Taste was quite complex, the slightest hint of sour, and noticeably sweeter than any other artisan bread I've had before, almost as though a sweetener had been added, but not to the extent that it could be classified as a sweet bread. 

Any ideas?  Malt powder maybe?