Cut the rice cakes and fish cakes into bite-sized pieces.
Slice the onion and green onion.
Add olive oil to a pan and sauté the onion and green onion.
Add low-sugar gochujang, soy sauce, and erythritol to the sautéed vegetables and mix well.
Add water, rice cakes, and fish cakes, then bring to a boil.
While boiling, add high-protein ingredients such as chicken breast or tofu.
Once everything is cooked through, season with black pepper to finish.