I don't think so. The fries looked like regular fries, no zest or anything that looked green for that matter. I didn't ask them how the fries had been prepared, but based on the taste Id say they just sprinkled some lime juice on top. That being said, it's entirely possible the lime was added at an earlier stage.

As mentioned above, I think the lime fries would have worked really well if they had been served with fish, but steak + lime fries just seemed weird to me.