Directions

• Combine 5 cups cold water, salt, soy sauce, honey, garlic, and ginger in a large bowl, stirring to dissolve salt and honey. Submerge pork roast in brine. Cover and refrigerate at least 18 hours or up to 24 hours.
• Preheat oven to 300°F with rack in center of oven. Remove pork from brine, and discard brine. Pat pork dry with paper towels; place pork on a small rimmed baking sheet lined with aluminum foil. Let pork stand at room temperature while oven preheats.
• Stir together honey, mustard, ginger, and salt in a small bowl until well combined.
• Brush 1 tablespoon glaze over pork. Roast pork in preheated oven until an instant-read thermometer inserted in center of roast registers 125°F, about 45 minutes, brushing pork with an additional 1 tablespoon glaze after about 20 minutes. (Internal temperature of pork will continue to rise during broiling and resting.)
• Stir together parsley, oil, ginger, vinegar, garlic, and salt in a medium bowl until combined. Season with additional vinegar to taste. Scatter half of the parsley sauce (about 2/3 cup) on a serving platter; set remaining sauce aside.
• Remove pork from oven; increase oven temperature to broil. Brush pork with remaining glaze (about 1 tablespoon). Return pork to center rack in oven, and broil until glaze browns and caramelizes in spots and a thermometer inserted in center of roast registers 140°F, 8 to 10 minutes. Remove pork from oven, and transfer to a large cutting board, reserving drippings in pan. Tent pork with foil, and let rest 10 minutes.
• Cut pork into thin slices, and arrange on parsley sauce on platter. Pour reserved drippings from cutting board and pan into bowl with remaining sauce; stir to combine. Spoon evenly over pork. Serve immediately.