Place chicken breasts between 2 sheets of waxed paper and gently pound with a meat mallet until about 1/2 inch thick. Season with salt.

Heat butter in a large, heavy nonstick skillet over medium heat until bubbly and starting to brown. Add chicken and cook about 10 minutes, turning occasionally, or until almost opaque in center and golden on both sides. Remove to serving plates.

Remove skillet from heat and let pan juices cool briefly. Add lemon juice, and stir to loosen brown drippings in bottom of pan. Spoon over chicken, season well with pepper, then sprinkle with parsley.