Season the chicken cutlets with salt and pepper. Heat a large nonstick skillet over medium-high heat. Spray with nonstick spray, and add the cutlets. Cook 2 to 3 minutes on each side- just until lightly browned and cooked through. Remove the cooked chicken to a plate and cover to keep warm.
Melt the butter in the skillet. Add the mushrooms, and cook over medium-high heat until mushrooms begin to brown and soften- about 3 minutes. Add the wine to the skillet, and continue to simmer until about half of the wine has evaporated (4 to 5 more minutes). Stir in the thyme.
Divide the mushroom mixture between the four cutlets for serving. Sprinkle fresh parsley on top, if desired.
If you prefer not to use wine in cooking, you can substitute chicken broth for the wine-- and if you're following WW and counting points... the use of chicken broth reduces the points!