Prepare your toppings: thinly slice the Chinese Sausage, finely chop the Scallions, and if desired briefly soak the Dried Tiny Shrimp in warm water for 3–5 minutes then drain and pat dry. Set the Pork Floss nearby for topping.
Melt a small knob of Unsalted Butter with a teaspoon of Neutral Oil in a small bowl or directly in the pan so the butter won't burn. Crack the Eggs into a bowl and beat lightly with a pinch of Salt.
Heat a nonstick skillet or griddle over medium heat and brush with some of the butter–oil mixture. Place one Rice Paper Sheet flat on the hot surface — it will begin to crisp quickly.
Immediately brush the top of the rice paper lightly with more of the butter–oil, then pour or gently spread the beaten egg over the rice paper to cover most of the surface. Sprinkle a tiny pinch more Salt over the egg.
Arrange the sliced Chinese Sausage and the drained Dried Tiny Shrimp over the egg, scattering the chopped Scallions and a little Pork Floss on top. Work quickly so the rice paper becomes crisp while the egg sets.
Cover the pan briefly (30–60 seconds) or lower the heat so the egg finishes cooking through and the toppings warm but the rice paper stays crisp. If you like, press gently with a spatula to help everything adhere.
Carefully transfer the finished bánh tráng nướng off the pan. While still hot, spread a thin line or zigzag of Mayonnaise and drizzle Vietnamese Chili Sauce to taste over the top.
Serve immediately—cut into wedges and enjoy while the rice paper is crackling and the toppings are warm and fragrant. Repeat with additional Rice Paper Sheet as desired.
