1. Heat a frying pan with olive oil and garlic over medium heat.
2. Add the mushrooms and a small pinch of salt when they turn golden brown. Reduce the heat to low and cover.
3. Add the rice cakes and optional parsley, and stir.
4. Combine the cup of water and the two tablespoons of fish broth in a bowl to make the broth.
5. After adding the broth, stir everything together and cook for seven minutes.
6.To thicken the sauce, combine the cornstarch and a tablespoon of water in the cup you used to hold the water, then transfer the mixture into the pan.
7. Remove and turn off the heat. This dish is ready to be served.