Place steak in large shallow dish. Whisk together fish sauce, lime juice, hoisin sauce, ginger, sherry, garlic, chili paste and sesame oil; pour over meat, turning to coat well. Cover and refrigerate for at least 8 hours or up to 24 hours. Let stand at room temperature for 30 minutes.
Place lettuce in large attractive salad bowl. In small saucepan of boiling water, cook snow peas for 2 minutes or until tender-crisp. Drain and refresh under cold water; drain again, pat dry and add to salad bowl.
On cutting board and using chef's knife, core red pepper and remove membranes and seeds; Cut into thin strips and add to bowl. Slice cucumber in half lengthwise; slice thinly crosswise and add to bowl. Add sprouts.
Reserving marinade, place steak on greased grill over medium-high heat or under broiler; cook, turning once, for about 10 minutes or until medium-rare. Transfer to cutting board and tent with foil; let stand for 5 minutes.
Meanwhile, in small saucepan, bring marinade to boil; boil gently for 5 minutes. Remove from heat. Whisk in vinegar and sugar; gradually whisk in olive oil. Let cool slightly.
Slice meat diagonally across the grain into thin slices; add to salad bowl. Pour dressing over top; toss gently until lightly coated. Serves 4.
Thai Pork Salad: Use pork tenderloin instead of flank steak. Grill, turning once, for 20 to 23 minutes or until just a hint of pink remains inside.
Thai Chicken Salad: Use 3 boneless skinless chicken breasts Instead of flank steak. Grill, turning once, for 8 to 10 minutes or until no longer pink inside.