1. Heat medium-sized skillet to medium-high and sauté breasts 1 minute per side. Reduce heat to medium-low and cook for 6 - 9 minutes or until a thermometer inserted into the thickest part of breast registers 170°F. Boil pasta according to package instructions.
2. Meanwhile, slice mushrooms. In a separate, medium-sized skillet, sauté mushrooms in olive oil on medium for 5 minutes. Add spinach and sauté until it begins to wilt, and season to taste with salt and pepper.
3. Drain pasta and return to pot, toss with butter and parsley.
4. Divide pasta among 4 plates. Place chicken breast on pasta, top with sautéed mushrooms and spinach. Serve

This recipe may easily serve 2 people instead of 4 people by using half the quantity of all ingredients.