Prepare the Rice Cakes: If using frozen rice cakes, soak them in cold water for 10-15 minutes to thaw.
Bring a pot of water to a boil, add the rice cakes, and cook until soft and chewy, about 3-5 minutes.
Drain, making sure to reserve about 1/2 cup (480 ml) of the starchy cooking water.
Mix the Sauce: In a small bowl, whisk together the soy sauce, dark sesame oil, sugar, and chile paste until the sugar is dissolved.
Set aside.
Sauté and Combine: Heat the neutral oil in a large nonstick or cast-iron skillet over medium-high heat.
Once shimmering, carefully add the drained rice cakes and a sprinkle of black pepper.
Stir-fry for 1 minute until they begin to get a little color.
Finish the Dish: Pour the prepared sauce over the rice cakes.
Cook, stirring constantly, for 2-3 minutes until the sauce thickens and coats every cake beautifully. If the sauce gets too thick or the pan looks dry, add a tablespoon or two of the reserved cooking water to create a glossy finish.
Serve: Immediately transfer the rice cakes to a serving dish.
Garnish generously with sliced scallions and toasted sesame seeds.
Enjoy while hot!
Don't overcrowd the pan. Use a large skillet to ensure the rice cakes get a chance to toast slightly rather than just steam, which enhances their texture.