I’m not sure how they do it exactly! But it’s on the menu at Tilt’n Diner in Tilton, NH LOL and probably other places too. And some places sell it in stores too I think but not specifically from that diner LOL And some mention Vermont or Maine too rather than New Hampshire so I think it’s just a general New England thing LOL but I have been to the Tilt’n Diner many times and have gotten those fries once. It was DELICIOUS. LOL you can also make it yourself I believe. I did see a bunch of recipes online when I was trying to remember which diner had it LOL I BELIEVE they just use maple syrup instead of honey but I’m not one hundred percent sure. LOL honey mustard is excellent with sweet potatoes too BUT! Maple mustard is NEXT LEVEL LOL