Empty contents of salad dressing mix package into a small bowl. Add water and mix well, then stir in olive oil and mix again. Note: DO NOT add vinegar as per package instructions.
Place chicken breasts 'wrong side up' in a lightly greased 9x13 inch baking dish. Put 1/2 teaspoon of the dressing mixture on each breast and spread over the surface.
Bake at 400 degrees F (200 degrees C) for 15 to 25 minutes, depending on the size of the breasts. Turn breasts over and spoon remaining mixture on to the topside. Bake for another 15 to 20 minutes, or until tops are golden brown and chicken is cooked through (juices run clear).
