1. Cook noodles according to package directions. Drain and rinse with cold water; drain. Coarsely chop noodles.
2. While noodles cook, freeze steak 5 minutes. Remove from freezer; cut across grain into 1/8-inch-thick slices. Sprinkle with salt and black pepper.
3. Heat a large cast-iron skillet over medium-high heat. Coat with cooking spray. Add beef; sauté 4 minutes.
4. Combine steak, noodles, lettuce, onion, cucumber, and habanero. Combine juice, sugar, and fish sauce; pour over noodle mixture, tossing gently. Sprinkle with basil.