I caught Papi Queso a few weeks ago at Food Truck Fridays in South End. After hearing so much hype, I was really looking forward to trying it, and I came HUNGRY. I split a green monster and a mushroom and leek with a friend, and while they were both delicious (I liked the mushroom and leek best), I felt they were expensive for what we got -- small sandwiches on wonderbread-sized toast -- and we waited for quite a while before our orders came up.
With that being said, they were definitely delicious: crispy and crusty on the outside and melty and warm on the inside. There were interesting varieties and flavor combinations as well. This truck is definitely worth a try, but be prepared for the long lines and to spend some chedda.