1. Pound the chicken breasts. Dredge with flour. 
2. Mix the parsley and lemon zest in a small bowl, set aside. 
3. Heat 1 tablespoon of olive oil in a large pan, cook mushrooms, remove from pan and set aside.
4. Over high heat, warm 2 tablespoons of olive oil. Add the chicken to the pan and sauté, turning once, until lightly browned, about 2 minutes per side. Transfer to a platter. Season with salt and pepper.
5. Add the garlic to the pan and sauté for 20 secondes. Add the broth, lemon juice, and white wine, bring to a boil, and deglaze the pan. Boil until slightly reduced, about 3 minutes.
6. Return the chicken to the pan and reduce the heat to medium. Cook chicken, about 10 minutes. Transfer chicken to a warm platter.
7. Add spinach to the pan and raise the heat to high and boil the pan sauce until reduced to 1/4 cup, about 5 minutes. Pour evenly over the chicken and sprinkle the parsley-lemon mixture evenly over the top.