In a large bowl, combine the pineapple juice, sugar, and soy sauce.
Marinate the pork in the pineapple juice, sugar, and soy sauce mixture for 1 to 3 hours.
Remove the pork from the marinade, and set the remaining mixture aside.
Heat the oil in a pan, and fry the marinated pork until it turns a light brown color (approximately 3 to 5 minutes).
Pour in the remaining marinade mixture along with the pineapple chunks and beef broth. Simmer for 45 to 60 minutes until the sauce thickens and the flavors meld.
Season with salt and pepper to taste.
Serve hot and enjoy your delicious meal!