Help in identifying a Thai condiment

At my favorite local Thai restaurant, they have a trio of spicy condiments available to add to your food. Of the three, one is chile-garlic sauce, one is a crushed dried red pepper of some kind, and the third is very mysterious to me.

It is a thick, dark (nearly black) chunky "paste" (ok, to chunky to be a paste, but I don't have a better word for it... 'jam' maybe?).

It is clearly made primarily of chilis, and I believe some kind of oil, but I'm not sure what else might be in it.

It has a very interesting flavour -- kind of roasty and spicy? Maybe some garlic in there too?

Any ideas as to what this mysterious roasty black chili "jam" might be?

In googling for Thai condiments, I keep finding several standard condiments, but none of them are this.

(I guess I could ask at the restaurant, but where's the fun in that? Plus I always forget when I am there...)