Daigaku Imo

Prep Time: 15 min Cook Time: 25 min
Daigaku Imo

Daigaku Imo

Prep Time: 15 min Cook Time: 25 min

About This Recipe

You might be familiar with those delicious little dishes of cubed sweet potatoes in a crunchy shell — called goguma mattang in Korean — that are sometimes featured along with the rest of your banchan. This take on the Japanese version, daigaku imo, is air-fried instead of deep-fried, giving them a creamy interior and crispy exterior.

The Benefits

Sweet potatoes are packed with beta-carotene; fiber; vitamins A, several Bs, and C; and minerals like iron, manganese, magnesium, and potassium. They also are a gut friendly vegetable since they are a good source of resistant starch that helps feed good gut bacteria. Air-fried cubes use a lot less oil, and studies show that air-fried tubers are almost acrylamide-free (acrylamide is a toxin produced in potatoes and sweet potatoes when cooked at very high temperatures). Black sesame seeds are high in several B vitamins and contain large amounts of calcium, magnesium, manganese, phosphorous, iron, and zinc. Eating sesame seeds appears to help lower blood pressure and reduce oxidative stress and damage to cells. 

Note: Feel free to use any type of sweet potato for this dish. If you don’t have an air fryer or convection oven, you can roast the sweet potato instead. But you’ll get crispier results if you use an air fryer or convection oven.

Equipment: Air fryer or convection oven


Serves 4 Servings
  • 2 medium sweet potatoes (about 1 lb or 450 g), peeled and cut into 1-inch cubes
  • 2 tsp cold-pressed sesame oil
  • ¼ cup (60 ml) maple syrup
  • 1 tsp soy sauce or tamari
  • 1 Tbsp (14 g) grass-fed butter
  • 1 Tbsp (9 g) black sesame seeds


  1. Step 1
    Soak the cubed sweet potatoes in a bowl of water for 10 minutes. Drain the potatoes, rinse, and drain again, then spread them onto a clean kitchen towel and pat to dry.
  2. Step 2
    In a large bowl, toss the sweet potatoes in the sesame oil and spread them evenly into the basket of your air fryer (or on a rimmed baking sheet, if using an oven). Air-fry at 380oF/195 oC (or roast at 400oF/200 oC) until the edges are crispy, 20 to 25 minutes.
  3. Step 3
    While the sweet potatoes are cooking, combine the maple syrup, soy sauce, and butter in a small pan and warm over medium heat until the butter is melted (or use a microwave for 30 seconds). Add the sweet potatoes and warm syrup mixture back to the avocado oil bowl, gently stir to coat, then transfer to a serving bowl and sprinkle on the black sesame seeds.

Substitutions: Use local honey instead of maple syrup, and avocado oil

Level Up: Make your own syrup with Okinawan crushed brown sugar (kokuto), which comes from only eight islands in the Okinawa archipelago. To make a rich simple syrup, dissolve the sugar in hot water at a 2:1 ratio by weight

Try It With: Bento lunchbox foods (like egg salad sandwiches and pickles), or as a snack with green tea

Zero Waste: Keep the skins on the sweet potatoes