Spread a thin, even layer of store-bought tomato sauce on the bottom of a frying pan to create a base.
Place frozen flat mandu in a single layer over the sauce, like pasta sheets, without overlapping.
Sprinkle mozzarella cheese generously and evenly over the mandu.
Pour more tomato sauce on top, then repeat layering with the remaining mandu and cheese in the same order.
Gently press down on the layers with a spoon, cover the pan with a lid, and heat over low heat until the cheese melts.
Once the cheese is fully melted, turn off the heat, let it rest to allow moisture and oil to settle, then cut into serving pieces and serve.
In a pan, layer ingredients evenly in order: tomato sauce, flat mandu, cheese.
Cover tightly and heat over low heat until the cheese is fully melted.
Turn off the heat, let cool slightly, then cut into bite-sized pieces and serve.
Cooking tips 💡
If the heat is even slightly too high, the sauce and mandu on the bottom can easily burn, so always maintain the lowest heat during cooking.
Because the cheese releases moisture and oil as it melts, letting it cool slightly after turning off the heat helps the dish set and makes clean cutting easier.
Using ketchup instead of tomato sauce will completely alter the flavor and harmony, so it is strongly recommended to use store-bought pasta sauce.