1. Sprinkle chicken with salt and pepper. In a 10-inch cast-iron or nonstick skillet heat oil over medium heat. Cook chicken in hot oil about 8 minutes or until browned, turning once. Transfer to a plate.
2. Melt butter in skillet. Add mushrooms; cook about 5 minutes or until mushrooms are browned and liquid evaporates, stirring occasionally. Add garlic; cook and stir 1 minute more. Stir in next five ingredients (through crushed red pepper). Bring to boiling; reduce heat. Simmer, uncovered, 5 minutes. Stir in tomatoes and Parmesan cheese.
3. Return chicken to skillet. Spoon sauce over chicken. Simmer, uncovered, 8 to 10 minutes or until done (165°F).
4. Serve chicken and mushroom sauce over gnocchi. If desired, top with a drizzle of balsamic vinegar and additional fresh oregano and Parmesan cheese. Makes 4 servings (1 chicken breast half + ¾ cup mushroom sauce each).
PER SERVING 729 cal., 26 g fat (8 g sat. fat), 153 mg chol., 1,527 mg sodium, 76 g carb., 7 g fiber, 5 g sugars, 52 g pro.