In a very large nonstick skillet, heat 1 tablespoon of the canola oil. Add the shallots and garlic and stir-fry over moderately high heat until lightly browned, about 2 minutes. Add the ground pork, brown sugar, black bean sauce, dried chiles, Maggi sauce and fish sauce and cook, breaking up the meat with a spoon, until it is browned in spots, about 10 minutes. Add 3/4 cup of the chicken broth and cook over moderately low heat until the broth has evaporated, about 8 minutes. Stir in 1 tablespoon of the vinegar. Transfer the ground pork mixture to a bowl and wipe out the skillet.
In a jar, combine the remaining 1/2 cup of chicken broth and 1/2 tablespoon of vinegar with the oyster sauce, sesame oil and sambal oelek. Seal the jar and shake the sauce to blend.
Bring a large pot of water to a boil. Add the Chinese broccoli and cook until it is crisp-tender, about 2 minutes. Using tongs, transfer the broccoli to a work surface and cut it into 1-inch pieces. Return the water to a boil and add the noodles. Cook just until al dente. Drain the noodles, shaking off the excess water.
Heat the remaining 1 tablespoon of oil in the skillet. Add the roast pork, ground pork, broccoli and noodles and toss to combine. Add the sauce and cook, tossing, until the noodles are evenly coated, 5 minutes. Add the scallion, transfer to a large platter and serve.