In a pot of boiling water, drop in the flat rice stick noodles for about 1 minute, stirring constantly to prevent noodles from sticking together. Remove from heat and drain in a colander. Rinse with cold water. Set aside. Heat the oil in a large wok and stir-fry the garlic and onion until golden brown. Add the pork, shrimp in water, and chilies. Stir-fry for 5 minutes and add the sugar, fish sauce, salt, lime juice, ketchup, black pepper, noodles, and bean sprouts. Stir well for 2 minutes. Transfer to a large serving platter and garnish with green onion, fresh coriander, and peanuts. (Serves 6-8)