From the lime, grate enough peel to measure 1/2 tsp. (2 mL) and squeeze juice; set aside.
Combine soy sauce, 1/2 Tbsp. (7 mL) fish sauce, garlic, 2 chopped chili peppers, lime juice and lime peel in large bowl. Stir in beef. Cover and marinate 20 minutes.
Remove beef from marinade; pat dry. Reserve marinade. Heat large nonstick skillet over medium-high heat and brown beef, stirring occasionally. Remove beef from skillet and set aside.
Add reserved marinade and Knorr® Beef Broth in same skillet and cook over medium heat, stirring frequently, until slightly thickened, about 5 minutes. Stir in arugula, bean sprouts, cilantro, basil and mint and cook, stirring occasionally, 3 minutes. Stir in beef and any juices. Spoon into 4 bowls.
Combine Hellmann's® Real Mayonnaise, sugar, remaining 1/2 Tbsp. (7 mL) fish sauce and remaining chili pepper. Stir in green onions and drizzle over salad. Garnish, if desired, with sliced red onion.