You'll find fish croquettes and rice cakes of all kinds in your typical Korean food store - fresh, cooled, frozen.
Make a fish broth (from anchovies) or simply use water. Cut the cabbage, fish croquettes and green onions into 2″ (5 cm) pieces.
Pour the broth into a large, deep pan and pour in all of the ingredients for the sauce, excluding the sesame oil and sesame seeds. Bring to a boil on a moderate stove, while stirring, in order for the chili paste (gochujang) to dissolve well.
Add the rice cakes and boil another 10 min. until the croquettes soften and the sauce thickens. Stir regularly, so that the rice cakes don't stick to the bottom of the container.
Finally, add the sesame oil and sesame seeds right before you turn off the oven. Serve the Tteokbokki right away.
This dish is not suitable for reheating in the microwave.