What should roasted pistachio oil smell like?

I've had a bottle of roasted pistachio oil sitting in my refrigerator for about two years now, that someone gifted me. Every day I open the refrigerator and it stares at me. Today I decided that enough was enough, and I'd try and finally get it out of my life by substituting it in a biscotti recipe.

It's over a year past the expiration date, but I've been storing it in the fridge ever since I got it. Now, I'm very familiar with what rancid neutral oils smell like, and even rancid olive oil. But I'm not sure how to detect whether a roasted nut oil has gone rancid. It has a very strong smell, but when I taste it, I don't notice any bitterness.

What should it smell like, if it is in fact still fresh?