Prepare the Shirataki: Rinse the Shirataki noodles thoroughly under running water. Boil them in plain water for 3 minutes to remove their distinct smell, drain, and cut them into 4-inch lengths with scissors.

Sauté the Base: Heat the vegetable oil in a large, heavy-bottomed pot over medium-high heat. Add the sliced beef and sear until lightly browned. Push the meat aside and add the onions, potatoes, and carrots. Sauté for 3 minutes until the vegetables are coated in the beef fat.

Braise: Pour the dashi stock, soy sauce, mirin, sake, and sugar directly into the pot. Bring the liquid to a rolling boil and use a spoon to carefully skim off the scum and foam that rises to the surface. Add the Shirataki noodles.

Simmer: Turn the heat down to medium-low. Cover the ingredients directly with a drop lid (Otoshibuta). Simmer gently for 20 to 25 minutes until the potatoes are incredibly tender and have absorbed the dark, savory broth.

Rest and Serve: Turn off the heat and let the Nikujaga rest in the pot for at least 30 minutes (crucial step, as the potatoes absorb the maximum flavor as they cool). Reheat gently before serving in deep bowls.