About 50 minutes before serving: Preheat the oven to 400.
In a small bowl, mix the bread crumbs, chopped parsley, minced garlic, 2 teaspoons of the olive or salad oil, and 1/4 teaspoon of the pepper, blending well.
Brush the dijon style mustard onto the skin side of the chicken-breast halves, then coat with the bread crumb mixture, firmly pressing the coating mixture into the chicken.
Spray an 11 X 7-inch glass or ceramic baking dish with non stick cooking spray.
Place the chicken, skin side up, in the baking dish.
Bake the chicken, without turning, for 20 minutes.
Meanwhile, cut each tomato, lengthwise, in half.
On waxed paper, mix the parmesan cheese, oregano, salt and 1/4 teaspoon of black pepper, stirring to mix well.
Sprinkle the cheese mixture over the tomato halves.
Add the tomatoes to the chicken in the baking dish and bake for an additional 15 to 20 minutes or until the coating on the chicken is crispy and browned and the juices run clear when the chicken is pierced with the tip of a knife.
To Serve: Toss the watercress with the salad dressing.
Arrange the tomatoes, chicken and the salad on 2 plates and sit down to eat.