Start by making the dipping sauce. Place the lime juice, sugar, fish sauce, and water in a small bowl. Mix until the sugar is dissolved. Add the garlic and chilies and mix well. Can be stored for up to 5 days in the fridge.
In a large bowl, combine rice flour, cornstarch, salt, sugar, and turmeric. Add water, and coconut milk, and mix until you have a smooth batter. Add the chopped spring onions and mix. Let stand at room temperature for 30 minutes.
In a medium mixing bowl, season the pork with a pinch of salt, and pepper. Set aside.
Heat a non-stick frying pan over medium-high. Add 1 tablespoon of oil and stir-fry the onion and pork until cooked through. Add the shrimp and stir-fry for 1 minute. Season with a pinch of salt and pepper. Transfer to a plate.
Wipe the pan clean if you use the same pan to make pancakes. Heat the pan again over medium-high and generously brush with oil. Stir batter to mix well. Then, add a ladleful of batter. Quickly, tilt the pan and swirl the batter to form a thin pancake. (You should hear distinct sizzling if the pan is at the right temperature.)
Cook until cooked through. The edges should start to pull away from the side of the pan after 3 to 4 minutes. These pancakes are traditionally cooked in a generous amount of oil. But, I make these pancakes with a little oil.If you like a crispy pancake, add more oil around the edges of the pancake and fry it longer.
Scatter one-half of the pancake with an adequate amount of pork, prawn, bean sprouts, cooked mung beans, and chopped spring onions.
Gently slide a wide silicone spatula underneath and fold the crepe in half to cover the filling. Cook it for another 30 seconds. then transfer to a plate. Repeat with the remaining batter and filling, stirring the batter each time before ladling.
Bánh xèo are best eaten right away as each is ready. Wrap a piece of the pancake with the filling inside a lettuce leaf. Add lots of fresh herbs and sliced vegetables. Then dip the bundle into dipping sauce and enjoy!