Sweet roasted potatoes, known as yaki imo in Japanese, are one of the favorite and most comforting winter snacks eaten in the country. Even though different varieties can be employed, yaki imo is usually prepared with traditional Japanese potatoes - large in size and with a dark purple skin and bright yellow center.
The potatoes are mainly sold by street vendors who grill them on hot black stones. Originally, street vendors had hand pulled trolleys, but today the majority of them prepares their delicacies on specially designed trucks equipped with traditional stoves and grilling stones.