How to Make It
Combine cabbage, 1 teaspoon lime juice, 1/2 teaspoon sugar, and 1/4 teaspoon salt; toss well to combine. Set aside at room temperature for 15 minutes.
Prepare rice noodles according to package directions. Drain and rinse with cold water; drain.
Toss steak with 1/2 teaspoon sugar. Heat a large skillet over high heat. Add oil; swirl to coat. Add steak to pan; cook 2 minutes. Turn steak over; cook an additional 30 seconds or just until browned. Remove from pan; keep warm.
Add 1/2 cup water to pan, scraping pan to loosen browned bits. Add curry paste and coconut milk, stirring well to combine; bring to a simmer. Reduce heat to low; simmer for 5 minutes. Stir in remaining 2 teaspoons lime juice, remaining 1 teaspoon sugar, and 1/2 teaspoon salt. Arrange about 1 cup noodles in each of 4 bowls; divide steak evenly over servings. Ladle about 1/2 cup broth over each serving; top each with about 1/2 cup cabbage mixture. Sprinkle remaining 1/4 teaspoon salt evenly over servings. Serve with lime wedges, if desired.