Mix the char siu sauce ingredients in a large bowl.
Pour the sauce into a large ziptop bag. Place the pork steaks in the bag and seal it. Roll the bag around making sure the sauce covers all the pork.
Place the bag in the refrigerator and let the pork marinate for 24 to 48 hours.
Once you're ready to remove the pork from the refrigerator, preheat your oven to 300°f / 150°c (convection) or 325°F/165°C (conventional) for 30 minutes.
Move the marinated pork steaks from the bag to a rectangular baking dish along with the marination liquid. Cover the dish tightly with foil and place it in the center of the pre-heated oven. Bake for 90 minutes.
During the last 30 minutes that the pork is roasting, make the marinade by mixing the maltose and hoisin sauce in a small mixing bowl. (Use a wet hand to add the maltose to minimize the stickiness.) Add a couple tablespoons of the water to loosen the mixture and let sit for about 10 minutes. After 10 minutes the mixture should combine easily.
Remove the pork from the oven and place it on a baking rack over a sheet pan. Set the oven to broil on its highest setting.
Optionally strain a couple tablespoons of the pork marinade and add to the glaze. Add more water if the mixture is too thick. Pour 2/3 of the mixture over the pork and brush the glaze to cover the pork uniformly.
Place the pork under the broiler and cook the first side for 8 to 10 minutes. Flip the pork and brush the remaining char siu glaze on the other side and cook for another 8 to 10 minutes. You want to see the glaze bubble and the pork to cook with the slightest char. Keep an eye on the pork as it can burn quickly. Remove from the broiler immediately when you see the glaze bubble.
Slice and serve immediately. Wrap any remaining pieces with foil and store in the refrigerator for up to 5 days or in the freezer for up to 3 months.
Notes
You can substitute honey for the maltose.
Double up on the Chinese miso if you can't find red yeast rice. If you can't find either ingredient, you can add a couple drops of red food coloring or just be happy without any red color. Your char siu will taste great with or without the red color.
You can use char siu pork in a number of ways including cubed in fried rice, over white rice with greens and in wonton soup.