I'm not sure how these got the name "college potatoes" (daigaku + imo) but they are tasty. I am trying out recipes from this new Japanese Shojin Ryori book and enjoyed this one! These would be really good at a party served with Asahi beer or sake and they are easy to eat with chopsticks or toothpicks. The only problem is they don't keep well overnight (the potatoes discolor in the fridge), so plan to make them the same day.
Buy "Japanese sweet potatoes" in the store, which are also called satsumaimo. They look like purple yams/sweet potatoes. Sweet potatoes are big in Japan: there are food carts with roasted satsumaimo with honey, and guys that walk around pulling wood fired ovens filled with sweet potatoes.
Wash and cut 2 Japanese sweet potatoes rangiri-style (into irregular chunks), making most pieces about the same size.
Combine in a large saucepan and bring to a simmer over medium high heat to dissolve the granules:
1/4 C sugar
1/4 C canola oil
2 TB water
1 tea soy sauce
1 tea komezu (rice vinegar)
1/2 tea salt
Dump the cut sweet potatoes into the pan in one layer across the bottom. Simmer gently for 3 minutes.
Stir, cover and cook for another 3 minutes until the potatoes are tender.
Now remove the lid and stir to cover the potatoes in the glaze, allowing to cook for 5-6 minutes with the lid off which will reduce the glaze.
Pour onto a serving tray and sprinkle with sesame seeds.
Let them cool before eating (I burnt the top of my mouth on one!!)