Prepare the ingredients: Soak the rice cakes for 5-10 minutes, mince the garlic and onion, and prepare the seasonings.
In high heat, fry the bacon and render all the fat. Afterward, remove the oil from the pan, slice the bacon into bitesize pieces, and place it back in the pan.
Add the onion to the bacon and saute them together until the onion is caramelized.
Drain the rice cakes and add it to the pan.
Add water, then season with garlic, gochujang, gochugaru, soy sauce, and sugar, then mix it thoroughly until the pepper paste is diluted and everything is coated with the sauce.
Add the sausage and mix it together.
Turn the heat to medium then add milk, heavy cream, and mozzarella cheese. Cook until the cheese has melted, and the tteok and sausage have softened up.
Once the ingredients are cooked and the sauce has slightly thickened, serve this hot, consume immediately, and enjoy!