Bring 4 quarts water and 1 teaspoon salt to a boil in a large saucepan. Add noodles to boiling salted water; cook according to package directions. During last 1 minute of cooking, add bok choy and spinach. Cook 1 minute or until greens wilt. Drain and rinse under cold water; drain well.
Combine 1/4 teaspoon salt, coconut milk, juice, soy sauce, vinegar, honey, and 1/4 teaspoon pepper in a small bowl, stirring with a whisk.
Combine 5 teaspoons oil, ginger, garlic, and curry in a Dutch oven over low heat; cook 5 minutes, stirring frequently. Remove from heat. Add reserved coconut milk mixture and noodle mixture; toss well.
Heat a large, heavy skillet over high heat. Cut beef across the grain into thin slices; sprinkle with remaining 1/4 teaspoon salt and the remaining 1/4 teaspoon pepper. Add remaining 1 teaspoon oil to pan; swirl to coat. Add beef to pan; sauté 2 minutes or until done. Add beef to pasta mixture; toss well. Sprinkle with sesame seeds.