Heat oil in a deep sided heavy skillet or saute pan with a lid, preferably with a non-stick coating, over medium heat. Add the chicken smooth side down. Saute, turning each piece with tongs or a plastic spatula until lightly browned, about 5 minutes per side. Half way through cooking add the shiitakes; lightly brown on both sides. Sprinkle with salt and pepper; remove chicken and shiitakes to a side dish.
Add the wine to the hot skillet and boil over high heat until reduced by half, about 3 minutes. Add the tomatoes, parsley, garlic and orange zest. Heat to boiling; stirring to combine ingredients. Return the chicken, shiitake and any juices on plate to the skillet. Cover and cook, over medium heat, 10 minutes or until the chicken is cooked through. Transfer the chicken to a heated platter; cover with foil. Turn the heat to high and boil the tomato mixture until slightly reduced and thickened, about 5 minutes. Add basil, if using. Season sauce to taste with salt and pepper. Garnish with basil and serve with Parmesan Orzo (recipe to follow).
Cook orzo in boiling, salted water, partially covered, stirring frequently to prevent sticking. When the water returns to a boil, uncover and boil until tender, about 15 minutes. Toss with the cheese and parsley.