Drain pineapple, reserving 1/4 cup juice; set aside. In a small bowl, combine 2 tablespoons cornstarch, 1 tablespoon water, garlic powder and 1 tablespoon reserved pineapple juice. Pour into shallow dish; add pork and turn to coat. , In a small bowl, combine the soy sauce, brown sugar, ginger, cayenne and remaining water, cornstarch and reserved pineapple juice until smooth; set aside., In a large skillet or wok over medium-high heat, stir-fry pork in 1 tablespoon oil until no longer pink; remove and keep warm., Stir-fry the broccoli, carrots and onion in remaining oil until tender. Stir cornstarch mixture and add to the pan. Bring to a boil; cook and stir for 2 minutes or until thickened. Add pork and pineapple; heat through. Serve with rice.