
Prepare the pork: Cut the pork along the grain into long strips about 2 to 3” (5 to 7.5 cm) wide and 1 to 1 1/4” (2.5 to 3 cm) thick. (*Footnote 4)
In a large bowl combine the soy sauce, hoisin sauce, oyster sauce, Shaoxing wine, sugar, molasses, garlic, five spice powder, salt, and food coloring (if using). Stir to mix well. Transfer the pork into a large ziplock bag. Pour 1/2 cup of the mixed sauce into the bag, saving the remaining sauce in a jar in the fridge to make the glaze later. Squeeze out as much air as possible and seal the bag. Massage the bag a few times so the pork pieces are covered evenly with the sauce. Transfer to the fridge and marinate overnight.
Soak the maltose jar in hot water, until the top loosens. You can also place the tablespoon in the hot water to heat up slightly. Grease your tablespoon with a thin layer of oil. (*Footnote 5)
Transfer 2 tablespoons of maltose into a 9” skillet. Add the rest of the mixed sauce into the same pan. Heat over medium heat and stir to melt the maltose, until brought to a simmer.
Simmer, stir constantly, for 3 minutes to thicken the sauce until it coats the back of a spoon. Once done, transfer the sauce to a bowl and set aside.
Preheat the oven to 450ºF (230ºC), or 425ºF (220ºC) convection.
Line a baking tray with a grilling rack, pour a layer of water into the tray without touching the rack.
Spread the marinated pork onto the grilling rack. Brush both sides with glaze.
Bake for 5 minutes.
Then glaze both sides of the pork, and bake for another 5 minutes.
Measure the temperature of the thickest part of the pork with a thermometer, it should register from 140ºF to 150ºF (60ºC to 65ºC). Roast longer if needed.
Turn on the broiler. Glaze both sides of the pork. Broil for 3 minutes.
Flip the pork. You can skip the glazing if the pork still looks wet, because you want the final broil to dry out the glaze a bit more so it sticks to the pork. But you can glaze again if the pork looks a little dry.
Broil for another 3 to 4 minutes. The pork should look glossy, with a thick glaze coating the surface and charred edges.
You can test the doneness by inserting a thermometer into the thickest part of the pork. It should read 150ºF to 155ºF (65ºC to 68ºC) (*Footnote 6).
Transfer the pork to a big plate and let rest for 10 to 15 minutes.
Then slice the pork and serve. (*Footnote 7)
Store the leftover pork and the glaze separately in the fridge for 4 to 5 days, or in the freezer for up to 2 months. When reheating the pork, glaze it again and roast at 350ºF (176ºC) until heated through. You can use the leftover glaze in char siu buns filling as the sauce instead of making it from scratch.