Preheat your oven to 150°C (300°F) with both top and bottom heat. Line a standard 28x28 cm (11x11 inch) baking pan with parchment paper, ensuring the paper goes up the sides slightly for easy removal.

In a medium bowl, whisk together the 40g corn oil and 40g whole milk until completely blended and emulsified.

Sift in the 40g of cake flour, and mix gently using a "Z" motion to ensure there are no lumps. Avoid stirring in circles as this may activate the gluten, making the cake dense.

Add the 4 egg yolks to this flour mixture. Using the same "Z" pattern, mix until you have a smooth, thick, and lump-free batter. Set aside.

In a separate, impeccably clean and dry bowl, place the 4 egg whites. Add a few drops of vinegar or lemon juice.

Using an electric mixer, start on low speed until the whites become frothy. Increase the speed to medium and gradually add the 30g of granulated sugar.

Continue whipping on medium-high speed until the meringue reaches the soft peak stage. This is critical: when you lift the beaters, the meringue should form a soft, droopy peak that curls over at the tip (like a bird's beak). Do not whip to stiff, upright peaks, as this will make the cake more prone to cracking when rolled.

Using your spatula, take about one-third of the whipped meringue and add it to the yolk batter.

Fold gently to lighten the thick batter until mostly combined.

Pour this lightened mixture back into the bowl with the remaining meringue. Now, fold very gently and carefully: cut through the center with your spatula, scoop from the bottom, and fold over the top. Rotate the bowl and repeat until no white streaks remain. The batter should be smooth, fluffy, and voluminous. Work quickly but gently to avoid deflating it.

Pour the batter into the prepared baking tray, holding the bowl about 30cm above the tray. This helps the batter spread evenly without creating large air bubbles.

Tilt the pan gently or use an offset spatula to spread it into an even layer.

Gently tap the tray on the counter 3-5 times to release any large air bubbles.

Evenly sprinkle a layer of seaweed pork floss and chopped green onions on top of the batter.

Place the pan on the middle rack of the preheated oven. Bake at 150°C (300°F) for 28-30 minutes, or until the top is a light golden brown and springs back lightly when touched.

Remove the cake from the oven and allow it to cool for a few minutes. Peel off the parchment paper from the bottom of the cake.

Let the cake cool to room temperature on a flat surface.

Once the cake has cooled, flip it over onto a new piece of parchment paper. Spread a thin layer of salad dressing on the surface of the cake, leaving a 1cm margin at the edges.

Sprinkle a layer of seaweed pork floss on top of the dressing. Gently press to help the floss stick to the dressing.

Use a sharp knife to trim off the two short ends of the cake at a slight angle (this helps the layers fit together snugly when rolling).

Starting from one angled end, use a rolling pin to help tightly roll the cake inward (the tighter you roll, the less likely it is to unravel after setting).

Use an offset spatula to gently press and compact it as you go.

Once rolled, refrigerate the cake for 30 minutes to set.

After the cake has chilled and set, use a sharp knife to slice it into 3-4 cm pieces. Serve and enjoy!