Combine 1/2 cup soy sauce, 1/3 cup honey, 1/3 cup ketchup, 1/3 cup packed brown sugar, 1/4 cup Chinese Shaoxing wine or dry sherry, 2 tbsp hoisin sauce, 1/2 tsp red food coloring (optional), and a pinch of Chinese five-spice powder in a bowl to create the marinade. Use a fork to poke holes in the 2 lb boneless pork loin. Place the pork in a zipper freezer bag and pour the marinade over it. Gently squish the bag to ensure the pork is well coated. Refrigerate for at least 2 hours, ideally overnight, to allow the flavors to fully penetrate the meat.
Preheat oven to 375°F (190°C) and spray a small pan with non-stick spray. Remove the marinated pork from the bag and place it in the prepared pan. Roast for 1 hour, or until the internal temperature reaches 145°F (63°C). Let the pork rest for 10 minutes, then slice 4 oz of the roast into thin strips, about 1/4 inch wide. I like to let the pork rest after roasting to keep it juicy and tender.
In a small bowl, whisk together 2 tbsp dark soy sauce, 2 tbsp regular soy sauce, 1 tbsp Chinese wine or dry sherry, 4 tsp cornstarch, 1/2 tsp sesame oil, 1 tsp creamy peanut butter, 1 tsp honey, and 1/4 tsp ground white pepper. Set the sauce aside for later use.
Bring a large pot of water to a boil and cook 8 oz uncooked lo mein noodles according to package instructions until just tender. Drain the noodles and set them aside. I recommend rinsing the noodles with cold water to prevent them from sticking together.
Heat 3 tbsp vegetable oil in a large, deep skillet or wok over medium-high heat. Add 1 clove garlic, crushed, and cook until just golden, then remove and discard the garlic. Add 1 cup mushrooms (thinly sliced) and cook until they begin to sear. Add 1 cup bok choy (sliced) and 2 tbsp carrots (julienned); stir-fry for 1 minute. Add the 4 oz Chinese roast pork strips (from Step 2) and stir to combine.
Add the cooked noodles (from Step 4) and the prepared sauce (from Step 3) to the wok. Toss everything together until the noodles are well coated and heated through. Cook for 2 minutes, stirring constantly to ensure the cornstarch thickens the sauce evenly. For an extra glossy finish, I sometimes drizzle a little sesame oil at the end.
Remove the wok from heat and transfer the lo mein to serving plates. Garnish generously with sliced scallions. Serve immediately while hot and enjoy your homemade pork lo mein!