Step 1

Arrange a rack in the bottom of the oven and heat the oven to 375ºF. Meanwhile, soak the rice cakes, prepare the remaining ingredients, and make the sauce.

Step 2

Place 2 pounds Korean rice cakes in a large bowl and add enough warm water to cover. Let soak for 20 minutes to soften and hydrate.

Step 3

If frozen, let 5 ounces eeomuk sit at room temperature to thaw enough to cut. Cut 3 tablespoons unsalted butter into small pieces. Thinly slice 3 medium scallions and reserve for garnish.

Step 4

Place 2 cups warm water, 1/3 cup gochujang, 3 tablespoons gochugaru, 3 tablespoons honey, and 3 tablespoons fish sauce in a medium bowl and whisk until combined.

Step 5

When the rice cakes are ready, drain them. Place in a 12-inch cast-iron skillet or 9x13-inch broiler-safe baking dish. Cut the fish cakes into bite-size pieces. Add the fish cakes to the baking dish.

Step 6

Pour the sauce over the rice and fish cakes. Stir until evenly coated and arrange into an even layer. Scatter the butter evenly on top.

Step 7

Bake until the rice cakes are puffy and the sauce is thickened, about 30 minutes. If you want a crispy top, switch the oven to broil and broil until browned in spots, 1 to 2 minutes. If using cheese, sprinkle with 1 cup shredded mozzarella cheese before broiling.

Step 8

Garnish with the scallions and 1 tablespoon toasted sesame seeds. Top with halved hard-boiled eggs if desired.