Bring a large pot of salted water to a boil. Add the noodles and cook as the label directs. Drain and rinse under cold water until cooled. Drain well and transfer to a large bowl. Toss with 2 teaspoons each chili sesame oil and vegetable oil.
Combine the pork with the scallion whites, ginger, 1 tablespoon soy sauce and the remaining 1 teaspoon chili sesame oil in a medium bowl. Combine the remaining 3 tablespoons soy sauce, the mirin, rice vinegar and 1 tablespoon water in a small bowl.
Heat the remaining 2 teaspoons vegetable oil in a large nonstick or cast-iron skillet over high heat. Add the pork mixture and cook, breaking up the meat with a wooden spoon, until browned, about 5 minutes; transfer to a large bowl, leaving any drippings in the skillet. Return the skillet to high heat and add the carrots and snow peas. Cook, stirring, until crisp-tender, about 3 minutes. Add the vegetables to the pork. Add the noodles to the skillet and cook, stirring, until warmed through, about 2 minutes. Add the soy sauce mixture and cook, stirring, until the noodles are coated.
Return the pork and vegetables to the skillet and toss to combine; season lightly with salt. Divide among bowls. Top with the scallion greens and serve with more chili sesame oil.