Wash the frozen prawns in cool water. When thawed, drain them in a colander.
Place the prawns on a cloth to dry and pat the moisture away using paper towels. You want each one to be free from any liquid.
Put the shrimp in a ziplock bag along with the pepper, chicken bouillon powder, fish sauce, salt and sugar.
Use a meat mallet (or any tool you have on hand) to pound the shrimp for 3 minutes, then set aside.
Heat up a pan with the oil and brown the lemongrass, chili, spring onion, purple shallots and garlic.
In a food processor, add the fried aromatics, shrimp and pork paste along with the baking soda and potato starch then blitz the contents until it forms a smooth paste.
Line a flat dish with banana leaf and wrap roughly 1/2 US cup paste around the sugar cane.Tip: Wearing gloves and coating it in a light layer of oil will stop the mixture from sticking. To make the surface smooth, roll the sugar cane in the palm of your hand.
Set up a steamer on high heat and steam for 5 minutes or until cooked.
Turn off the heat then lightly brush egg yolks on the steamed chao tom and let it rest in the steamer for 1 minute. This step will allow the yolk to form a glaze over the meat without overcooking.
Set up a deep frying station and cook the chao tom for 5-10 minutes or until golden brown.
Serve immediately with bánh hỏi (Vietnamese woven rice noodles) and fresh herbs!