Mix the shrimp with the cornflour and season with salt and pepper
Heat half the sesame oil in a wok over high heat. Fry the shrimp rapidly until just done, only 1-2 minutes. Lift out with a slotted spoon.
Add the other half of the sesame oil to the wok with the carrots and scallion whites. Stir fry for about 3 minutes.
Add the shiitake mushrooms and the wood ear mushrooms. Fry for another 3 minutes.
Add the cabbage and the scallion greens. Stir fry just until wilted, not more than 2 minutes.
Add the egg and stir rapidly for 30 seconds until cooked through and distributed throughout the mix.
Return the shrimp to the pan and turn off the heat. Stir through, and transfer to a serving bowl.
Serve with pancakes, hoi sin sauce, fresh cilantro, and any other toppings of your choice.