Step 1

For the Pork: In a small bowl, stir together egg white, cornstarch, rice wine, and salt until thoroughly mixed. Place sliced pork in a bowl pour cornstarch mixture on top, tossing to coat thoroughly. Refrigerate for 30 minutes.

Step 2

Fill the wok with water and bring to a boil over high heat, then add oil. Add pork, stirring with chopsticks or a strainer to separate the pieces, and cook until pork is opaque and nearly cooked through, about 40 seconds. Drain work into a colander and shake well to remove excess water. Wipe wok clean and dry thoroughly.

Step 3

For the Stir-Fry: In a small bowl, stir together pineapple juice, tomato paste, rice vinegar, soy sauce, sesame oil, and cornstarch.

Step 4

Heat vegetable oil in wok over high heat until smoking. Add bell peppers and onions and stir-fry for 30 seconds. Add pork and continue to stir-fry until browned in spots, about 2 minutes. Using a spatula, push pork and vegetables up side of wok, then add sauce so that it pools in center. Bring sauce to a boil, stirring, then toss with pork and vegetables until sauce thickens and coats them well. Turn off heat and toss in pineapple chunks. Transfer to a platter immediately and serve with rice.