Pour 1/4 cup Wish-Bone® Italian Dressing over shrimp in large, shallow nonaluminum baking dish; turn to coat. Cover and marinate in refrigerator, turning occasionally, up to 1 hour.
Remove shrimp from marinade, discarding marinade. Grill or broil shrimp, turning once and brushing with 1/4 cup Dressing, until shrimp turn pink. To serve, toss remaining 1/4 cup Dressing with greens and arrange on serving platter. Top with grilled shrimp and radishes.