Peel the potatoes and cut them into large chunks. Place into a mixing bowl and soak them in cold water for 10 minutes.
Then measure out 1 cup of cold water. If you have dashima, drop in a small piece into the cup of cold water. (If you don't have dashima, ok to skip).
Dice the chili pepper into small slices.
Now make the braising sauce: Thoroughly mix Soy Sauce (4 Tablespoons), Mirim (2 Tablespoons), Sugar (1 Tablespoon), Sesame Oil (1 teaspoon!) and a few cracks of Black Pepper.
Before we start cooking, drain the water from the potatoes. Let the potatoes sit in a strainer and drip-off excess water.
Now, let's add some oil into a frying pan. When the oil is hot, place in the potatoes chunks and chili pepper slices. Stir-fry them around until the potatoes are about halfway cooked through. Now, give your braising sauce a quick mix and carefully add it into the frying pan. Stir-fry everything in the sauce for ~10 seconds. Now, add in the dashima water (1 cup). And set at timer for 5-7 minutes.
Let it reduce for 5-7 minutes - or until there is only a small layer of sauce. (Note: If it seems like your potatoes are getting overcooked and there is still alot of broth leftover in the pan, pour-out the excess broth and leave only a small layer left.) When there is a small layer of sauce left, add in the Corn Syrup (1 Tablespoon). Give it one final gentle mix. Turn off heat and plate.