Vividly red and deeply bronzed, char siu is an iconic Chinese-restaurant dish the world over, and for good reason: Fatty pork and deep, sweet roasty flavors have an ability to ennoble a simple bowl of white rice. Sometimes made with pork belly or loin, this version uses pork shoulder, which offers a good mix of rich and lean. Originally from Guangdong, the dish can skew sweet at some takeout spots in the U.S and often gets its rosy color from artificial food coloring. Jew dials down the sweetness, intensifies the spice with Sichuan peppercorns, and colors it naturally with beet juice. Take care when working with beet juice, as it can easily stain clothes.
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.