Directions: Heat the peanut oil in a large wok until very hot. Add the garlic and saut, briefly. Add the pineapple, tomato, cucumber, and stir fry for 2 minutes. Add the lemon juice, sugar, Thai fish sauce, oyster sauce, ketchup, and water. Bring the mixture to a simmer and add the prawns. Simmer gently, stirring often until the prawns are cooked through. Stir in the scallions and serve over Thai noodles. Garnish with chopped cilantro.