I'm in the process of researching mortar and pestles, preferably mortar and pestles that can make short work of garlic and ginger in relatively large quantities (about 2 heads of garlic and about half that quantity of ginger- 8 oz-ish).
I've seen so many food/travel shows that it's all a bit of a blur, but I faintly recalling seeing a show where one of the cooks used two flat-ish stones for grinding- stones that they were able to make quick work out of just about anything. The other nice aspect was, that, unlike most stone M&Ps, these were not hulking masses. The Indian sil batta and Mexican metate y mano are close, but what I saw wasn't a rolling pin.
I'm sort of picturing one large flat slightly bowled stone (like the sil batta) and a flat stone pestle. For some reason, the pestle feels like it's too large to use with one hand, but I don't recall the cook using two hands to use it. Perhaps it was just small enough to use with one hand- maybe 6" square. Bottom line, it was two pretty big flat-ish stones.
Does this ring a bell with anyone?