Bring 2 quarts water to a boil in a large saucepan. Add soba; cook 4 minutes. Add edamame; cook 2 minutes or until soba is done. Drain and rinse with cold water; drain. Place soba mixture in a large bowl. Add Basic Grilled Flank Steak, bell pepper, carrot, and onions; toss well to combine.
Combine vinegar and remaining ingredients, stirring with a whisk. Drizzle over soba mixture; toss gently to coat. Cover and chill.