Boil fresh Chinese lo mein noodles until just cooked, according to package directions. Drain and rinse under cold water. Set aside.
Whisk all sauce ingredients together in bowl. Set aside.
Trim pork of excess fat and cut into thin strips (about 1/4 inch wide by 2 inches long). In a bowl, combine baking soda and 1/2 cup cold water. Add pork, stir and let sit at room temperature for 15 minutes. Rinse pork in cold water. Drain well and pat dry with paper towels. Add pork back to the rinsed and dried bowl. Stir in 2 tablespoons of the sauce and mix well.
Heat 1 tablespoon oil in a large (12 inch) cast iron pan or wok on medium-high heat. Add the ginger, garlic and white scallions bottoms and stir-fry for 30 seconds. Add cabbage, Chinese broccoli, if using, and carrots. Cook until vegetables are charred in spots and just softened, 3-5 minutes. Remove to a plate.
Add the last tablespoon oil. Make sure pan is hot and add pork in a single layer. spreading it out as much as possible. Let pork sear on one side until crisp and brown, 2-3 minutes. Stir and cook another minute, until just cooked through. Add the sauce. Stir in the vegetables and noodles and toss well to combine. Sprinkle over scallion greens and serve immediately.