Brush beef with 1/4 cup of Thai Dressing. Cook beef in heated oiled grill pan (or BBQ) until browned both sides and cooked as desired. Remove from heat, cover; stand for 10 minutes before slicing thinly.
Meanwhile, halve cucumbers lengthways, scoop out and discard seeds; slice thinly. Cut tomatoes in quarters lengthways, remove and discard seeds; slice thinly. Just before serving; toss beef in medium bowel with cucumber, tomato, sprouts and remaining dressing; sprinkle with mint leaves.