Heat oven to 425°F. Spray 15x10x1-inch pan with nonstick cooking spray. Arrange turkey tenderloins, potatoes and artichoke hearts in sprayed pan. Brush with about half of the salad dressing.
Bake at 425°F. for 30 minutes.
Remove pan from oven. Turn turkey over and stir vegetables. Add mushroom slices, tomatoes and onions to pan; brush turkey and vegetables with remaining salad dressing.
Return to oven; bake an additional 15 to 20 minutes or until turkey is fork-tender and juices run clear. To serve, cut turkey crosswise into slices. Serve any pan juices with turkey and vegetables. If desired, season to taste with salt and pepper.