Bring rice and 2 cups water to a boil in a saucepan. Reduce heat to medium-low, cover, and simmer until the rice is tender and the liquid has been absorbed, 20 to 25 minutes.
Place sausages into a skillet with 1/2 cup water over medium heat, cover, and cook until heated through, about 5 minutes. Thinly slice sausages.
Combine sausages with onion, green pepper, and celery in a large skillet over medium heat; cook and stir until vegetables start to soften, about 5 minutes.
Stir tomatoes, beef broth, pineapple, garlic powder, black pepper, and brown sugar into sausage mixture. Cook and stir until brown sugar has dissolved and mixture comes to a simmer.
Whisk reserved pineapple juice with cornstarch in a small bowl until smooth. Stir cornstarch mixture into sausage mixture and cook until sauce thickens and turns clear, about 2 minutes.
