In a medium bowl, combine cabbage, 1 tsp. salt, mustard oil, and vinegar and stir to combine. Set aside.
For the marinade, combine Shaoxing rice wine, oyster sauce, sugar, 1 1⁄2 tbsp. honey, red tofu, garlic, 2 tbsp. soy sauce, five-spice powder, fennel, coriander, Sichuan pepper, beet juice, and remaining 1 tbsp. salt in a blender and process until smooth.
Cut pork into rectangular strips approximately 8-in. long, 3-in. wide, and 2-in. thick.
In large plastic resealable freezer bags, combine pork and marinade and refrigerate overnight or up to two days.
Preheat oven to 425°. Place a cooling rack on a sheet pan (to allow air to flow around pork while it cooks). If you don’t have a cooling rack, lightly oil a sheet pan or line with parchment paper. Remove pork from marinade and place on cooling rack (if you’re not using a rack, let pork drain before placing on prepared sheet pans). Reserve marinade.
Place 2 cups marinade and remaining 2 tbsp. soy sauce in a medium saucepan over medium heat and simmer 5 minutes, or until reduced by one-fourth. Turn off heat and stir in remaining 4 tbsp. honey.
Place pork in oven and cook for 30 minutes. Baste pork with reduced marinade and cook 10 minutes more. Turn pork over, baste, and cook 10 minutes more. If pork is browning too quickly and starting to char, lower heat to 400°. Cook pork until caramelized and brown, about 10 minutes more. Let rest 10 minutes, then slice into 1∕3-in. slices. Serve with cabbage mixture on the side.