Reduce Marsala wine in large skillet until syrupy consistency. Stir in water and Knorr® Homestyle Stock - Chicken and bring to a boil. Whisk in cornstarch blended with 1/4 cup water until smooth and slightly thickened.
Rub chicken with 1 tablespoon olive oil. Grill in hot grill pan, turning once, until chicken is thoroughly cooked. Remove chicken from grill pan; keep warm.
Heat remaining 2 tablespoons olive oil in another skillet and cook mushrooms until tender and starting to brown. Add onion and garlic and cook until tender.
To serve, slice chicken into halves. Arrange 1/2 of the mushrooms on serving platter, then top with chicken and remaining mushrooms. Pour sauce over and sprinkle, if desired, with chopped fresh parsley.
Fire up the grill for some mouthwatering grilled chicken. Follow these tips to sizzle your way to tender, flavorsome chicken.