How to Make It
Combine honey, vinegar, ginger, and 3/4 teaspoon pepper in a small bowl, stirring with a whisk. Place 4 teaspoons honey mixture in a small bowl; set aside.
Heat a grill pan over medium. Coat pan with cooking spray. Sprinkle pork with 1/2 teaspoon salt. Add pork to pan; grill 12 minutes, turning to brown on all sides. Brush pork with remaining honey mixture; cook 6 minutes or until a thermometer inserted in the center registers 145°F. Place pork on a cutting board. Let stand 5 minutes. Cut across the grain into 16 slices.
Cut cucumber into 1/4-inch slices. Combine cucumber, watercress, radishes, oil, and juice in a large bowl. Add remaining 1/4 teaspoon pepper and remaining 1/4 teaspoon salt; toss. Divide pork evenly among 4 plates; drizzle evenly with the reserved 4 teaspoons honey mixture. Serve with salad.