In a large skillet, coated with nonstick cooking spray, heat the olive oil and sauté the breasts about 5 minutes on each side, until lightly browned.
Season with salt and pepper to taste and move to a 3-quart oblong dish coated with nonstick cooking spray.
Cook the spinach according to the package instructions; squeeze and drain well.
Top each chicken breast with the cooked spinach and a slice of mozzarella cheese.
Add the chicken broth to the same pan used to sauté the breasts, then add the wine and lemon juice, scraping the pan to remove the drippings, and stirring until heated. Pour the sauce over the chicken.
Bake for 20 minutes, or until the chicken is done. The cheese should be melted and the chicken heated thoroughly.