In a large saucepan over medium heat, brown pork and onions in oil.
Add bamboo shoots, shrimp, mushrooms and broth.
Bring to a boil.
Reduce heat; simmer 30 minutes.
Add melon; bring to a boil.
Stir in lime juice, soy sauce, hoisin sauce, ginger and garlic paste; simmer 10 minutes.
Slowly stir in cornstarch mixture, until slightly thickened.