How to Make It
Freeze the pork for 15 minutes. Meanwhile, in a microwave-safe bowl, cover the shiitake mushrooms with hot water and a paper towel. Microwave at high power for 3 minutes. Let the shiitake stand until softened, about 15 minutes. Drain and press out the water. Cut off and discard the stems. Thinly slice the caps.
Slice the pork 1/4 inch thick. Stack the slices and cut them into 1/4-inch-wide strips. Transfer the pork to a medium bowl and toss with the cornstarch, sherry, soy sauce, white pepper and 1 tablespoon of the oil.
Heat a large skillet until almost smoking. Add 1 1/2 tablespoons of the oil and heat until small puffs of smoke appear around the edges. Add the pork and stir-fry over high heat until nearly cooked, 30 seconds; transfer to a plate. Add the remaining 1 1/2 tablespoons of oil to the skillet, then add 1 teaspoon of salt and swirl to combine. When the oil is shimmering, add the shiitake caps and half of the cabbage and stir-fry over high heat until just wilted. Add the remaining cabbage and stir-fry until crisp-tender, 1 1/2 minutes longer. Return the pork to the skillet and cook until just heated through, 1 minute. Serve right away, with rice and chile sauce.