Divide taro into 125 g and 250 g, steam over medium heat for 15-20 minutes, or until softened.
Slice shallot thinly. Finely chop soaked dried shrimp. Cut soaked mushroom into small pieces.
Drain soaked white rice (NOT fragrant rice/beras wangi).
Put white rice into blender, add in 125 g of water from soaking ingredients, blend over high speed for about 3 minutes until fine. Add in 550 g of water from soaking ingredients, 125 g of steamed taro, salt, sugar, ground white pepper and five spice powder, blend until well mixed. (Reminder: If the water from soaking ingredients is not enough, top up with plain water. Stop a few times during blending to prevent overheating of machine.)
Add shallot to 200 g of cooking oil, mix well. Cook over medium-high heat until lightly browned. Off the heat, continue to cook with residual heat until golden brown. Put fried shallot on a sieve to drain off the oil, set aside to cool.
Heat up 5 tbsps of oil, add in dried shrimp, cook over medium heat for 2 minutes. Add in mushroom and 250 g of steamed taro, cook for another 3 minutes until fragrant.
Off the heat, add in rice mixture gradually, mix until combined.
Cook over medium heat until thickened.
Pour batter into 8-inch/20-cm square baking pan (coat with oil and line with baking paper), smooth the surface with wet spatula.
Steam taro cake over medium heat for 45 minutes.
Off the heat, top with spring onion and chili, cover and let it sits for 5 minutes before removing from steamer.
Set aside to cool completely before unmoulding the taro cake
Cut taro cake into pieces using plastic knife after unmoulding.
Garnish with some fried shallot before serving.