Slice the pork into 2 inch by 1/2 inch strips. Melt the shortening in a large frying pan or skillet over medium heat. Add pork and cook, stirring constantly, until pork browns. Add water, bouillon cubes and 1/2 teaspoon salt. Mix well and cover; simmer until tender, about 1 hour.
In a medium saucepan, combine brown sugar and cornstarch. Stir in reserved pineapple juice, soy sauce, vinegar and 1 1/2 teaspoons salt. Cook over medium heat, stirring occasionally, until thickened.
Add sauce cooked pork; mix well. Stir in pineapple, green pepper and onion. Cook over low heat until vegetables are tender, about 20 minutes.