Pre-made rice cakes can be submerged in warm water for 20 minutes, or until they are slightly softened. This should be set aside so that you can move on to the next step. This extra step is unnecessary if your rice cakes are fresh and soft to the touch.
Make the stock. Add all the stock ingredients to a large saucepan. Bring to a boil over medium heat. After 10 minutes, reduce heat to a simmer or medium-low. Strain the stock and discard any remaining ingredients. The stock should be returned to the saucepan.
Combine all seasoning ingredients in a small bowl. Stir until well combined. Stir the seasoning mixture into the saucepan.
Refrigerated rice cakes: Drain the water completely after the rice cakes have soaked.
Add the rice cakes, and fish cakes to your saucepot. Tongs are used to stir the rice cakes and fish cakes so that the seasoning is evenly distributed.
Turn the heat up to medium. Stir frequently to ensure that the rice cakes don’t stick on the bottom of your pan. Cook for another 15 minutes, or until the liquid thickens to maple syrup consistency. The sauce should be smooth and soften the rice and fish cakes.
Turn off the heat, then add the chopped big green onion and the hard-boiled eggs. Allow the eggs and green onions to heat for 2 minutes.
Sprinkle with sesame seed and serve.