- FOR THE TAPENADE: Put all the tapenade ingredients in the bowl of a food processor, and pulse to make a coarse puree.
- Cut a horizontal slit in each chicken breast to create a pocket, and stuff with the tapenade. Set aside until serving time. When ready to cook the chicken, preheat the oven to 180ºF. Heat the olive oil in a large skillet, and when hot, season the stuffed breasts with 1/2 teaspoon each salt and pepper, and arrange them side by side in the skillet. Cook over medium heat, covered, for about 3 minutes on each side, and then transfer to a platter, and keep warm in the 180ºF oven.
- Add the mushrooms and onion to the skillet, and sauté for about 2 minutes. Add the Manischewitz Chicken Broth, and reduce the contents by boiling for 2 minutes. Add additional salt and pepper to taste.
- Serve a chicken breast on each of four hot plates, and add any juice that has accumulated around them on the platter to the mushroom sauce in the pan.
- Divide the mushrooms and sauce among the servings, spooning it over the chicken breasts, and sprinkle the parsley or chives on top. Serve.