Cut pork horizontally in half to split the loin; cut each half crosswise into 1/4 inch thick slices. Combine pork, 1 tablespoon soy sauce, and curry powder in a large bowl. Set aside.Combine peanut butter, brown sugar, and remaining 2 tablespoons of soy sauce, lime juice, and sesame oil in a small bowl until well blended. Gradually stir in water until smooth. Set aside.Peel cucumbers and cut lengthwise in half. Scoop out seeds. Slice cucumbers into thin slices. Thinly slice onion. Combine cucumbers, onions, granulated sugar, vinegar and salt in a large bowl. Set aside.Heat the wok over high heat about 1 minute or until hot. Drizzle vegetable oil into the wok and heat 30 seconds. Add pork mixture and stir fry until well browned on both sides. Reduce heat to mediumAdd peanut butter mixture to the wok and heat through. Transfer pork to a serving platter. Spoon cucumber mixture around pork.