Drain the pineapple, reserving ¼ cup of the juice. In a large bowl or shallow dish, combine 2 tablespoons of the cornstarch with 1 tablespoon of the water, the garlic powder and 1 tablespoon of the reserved pineapple juice. Add the pork and toss to coat it.
In a small bowl, combine the soy sauce, brown sugar, ginger, cayenne pepper, the remaining ½ cup of water, 1 tablespoon of the cornstarch and the reserved pineapple juice. Whisk until the sauce is smooth.
In a large skillet or wok, heat 1 tablespoon of the canola oil over medium-high heat. Stir-fry the pork until it’s no longer pink, then remove it and keep it warm.
Stir-fry the broccoli, carrots and onions in the remaining 1 tablespoon of cooking oil, until the vegetables are tender. Stir the soy sauce mixture and add it into the pan, then bring the sauce to a boil. Cook, stirring consistently, for two minutes or until the sauce has thickened. Add the cooked pork and the pineapple and heat everything through, then serve it on a bed of rice.
