Partially freeze meat. Thinly slice across the grain into bite-size strips. Set aside. Drain pineapple, reserving 3/4 cup of juice. Set aside.
For sauce, stir together reserved pineapple juice, cornstarch, Worcestershire sauce, bouillon granules, and cumin. Set aside.
Spray a wok or large skillet with nonstick spray coating. Preheat over medium-high heat. Add green onions and stir-fry for 1-1/2 minutes. Add bean sprouts and stir-fry 1 minute or until vegetables are crisp-tender. Remove from wok.
Add pork to wok and stir-fry for 2 to 3 minutes or until done. Push pork from center of wok.
Stir sauce and add to center of wok. Cook and stir until thickened and bubbly. Cook and stir for 1 minute more.
Return vegetables to wok. Add tomatoes and pineapple. Stir everything together to coat with sauce. Cook and stir for 1 minute or until heated through. Serve over shredded romaine. Makes 4 servings.