How can you go wrong with pesto, tomatoes, and mozzarella? Answer: You can't.
boneless, skinless chicken breasts (I like the thinly-sliced ones!)
1/2 c refrigerated pesto
2-3 plum tomatoes, sliced
block of part-skim mozzarella cheese, sliced
Preheat oven to 400 degrees. Line a baking sheet with foil and spray with cooking spray. Put the pesto in a medium bowl and toss chicken to coat. Put chicken on baking sheet and bake for 20-25 min or until chicken is no longer pink. Remove from oven and cover with tomatoes and mozzarella. Bake for an additional 5 min or so until cheese is melted.