There are a few places selling ปาท่องโก๋ in Chiang Khan but this is the original and best!  I tried สังขยาใบเตย and หมูสับผักรวม and both were good but I think มูสับผักรวม is the best choice. He has a stall in the fresh market in the morning and then sells on the walking street in the evening. Don't miss!