Preheat oven to 350 degrees Fahrenheit. Slightly oil a baking dish. Put rice flour and 1 cup of water into a pot and mix with a spatula. (The water-rice flour proportion can be adjusted to achieve your desired texture. More water makes the cake softer.) Keep stirring and slowly add 4 cups of water over medium heat. Once the mixture becomes a sticky rice dough, turn off the heat and pour into the baking dish. Heat olive oil in a different pan, add onion sauté for 20 seconds, and then add the smoked salmon, shiitake mushrooms, rice wine, sugar, five-spice powder and soy sauce. Continue to cook for about 2 minutes. Remove from heat and pour over the rice dough in the baking dish. Cover and bake for 45 minutes. Cut out desired portion to serve. Use additional soy sauce if you wish, and garnish with some cilantro.