Lightly oil a large nonstick saucepan. Take a handful of loosened wantan noodles (See Recipe Notes 1) and carefully arrange them in a pancake shape on the saucepan. Cook till the bottom is crispy and lightly browned, then flip to cook other side. Place pancake on serving plate.
Now, prepare the gravy. In a wok, heat up 1-2 tbsp of oil. Add in ginger, garlic and shallots. Fry until fragrant. Put in the prawns shell side down and let cook until shells start to turn red.
Into the wok, add prawn stock and bring to the boil. Once prawns are cooked, remove from wok and arrange them on the noodle pancake.
Back to the wok, add carrots and cabbage. Bring to the boil again. Cook until vegetables are tender. Add some water if gravy gets too dry. Add spring onions. Stir in cornflour solution.
Turn off heat and stir beaten egg into the gravy. Add salt, sugar and white pepper to taste.
Pour sauce over prawns and noodles. Serve at once.