In a bowl, combine the five-spice powder, soy sauce, honey, and sesame oil. Add the beef slices and marinate for at least 10 minutes.
Preheat the grill to medium-high heat. Grill the beef slices for 2-3 minutes per side, or until cooked to your desired doneness. Remove from heat and let rest for a few minutes.
In a large salad bowl, combine the mixed salad greens, cherry tomatoes, cucumber, red onion, cilantro, and peanuts. Toss to combine.
Slice the grilled beef into thin strips and arrange on top of the salad.
Serve the salad immediately and enjoy!