Tofu - Cooking technique for firm/chewy edges? This may be a very basic question and I've just somehow not been doing it properly.

When I get tofu in the prepared foods department or the Chinese buffet, it's prepared in cubes that seem to have been marinated and then cooked in some way that makes it... not "crispy" as I see a lot of advice about online, but more of an al dente sort of firmness or chewiness?   

When people talk about crispy tofu, is this the consistency they're talking about?  The "chewy" texture my favorite style of tofu, but I've never been able to replicate it following the usual crispy-tofu directions, and am not sure how else to describe it.
Often they'll freeze the tofu before cooking it to give it a much meatier texture. That may be what you're describing. 

"Crispy" tofu I usually think of as quite literally fried tofu.