To prepare the rice cakes, combine the rice flour, tapioca starch, water, and salt in a large bowl. Whisk until smooth and free of lumps. Let the batter rest for at least 15 minutes to allow the starch to hydrate fully.

While the batter rests, soak the dried shrimp in hot water for 10 minutes to soften them. Drain, then finely chop or grind the shrimp using a food processor. This topping adds a signature flavour and texture to Bánh Bèo.

Prepare the scallion oil by heating 1/4 cup of vegetable oil in a small pan over medium heat. Once hot, add the sliced green onions and stir gently for about 1-2 minutes until softened but still bright green. Remove from heat and set aside.

In another pan, heat 2 tablespoons of vegetable oil over medium heat. Add the minced garlic and shallot, cooking until fragrant and golden, about 1-2 minutes. Add the chopped shrimp, sugar, and fish sauce. Stir well and cook for 3-4 minutes, then set aside. This topping provides a savoury depth to each rice cake.

Prepare a steamer by filling it with water and bringing it to a gentle boil. Place small, shallow heatproof dishes (or ramekins) in the steamer tray, allowing steam to circulate around each one. Lightly oil each dish to prevent sticking.

Pour a small amount of batter into each dish, just enough to create a thin layer. Cover and steam for 4-5 minutes, or until the rice cakes turn opaque and are firm to the touch. Repeat until all batter is used, removing the cakes to cool slightly between batches.

While the cakes are steaming, prepare the fish sauce by combining the fish sauce, water, sugar, and lime juice in a bowl. Stir until the sugar dissolves, adjusting the seasoning to taste with more lime or chili slices if desired.

To serve, spoon a bit of the dried shrimp topping over each rice cake, followed by a drizzle of scallion oil. Serve with the prepared fish sauce on the side for dipping or drizzling. Bánh Bèo is best enjoyed warm, allowing each bite to highlight the tender texture of the rice cake, the savoury shrimp topping, and the bright scallion oil.