In a medium frypan heat oil for frying. Coat chicken breast with flour and add to frypan. Saute until golden brown (presentation side down) and pepper to taste.
Turn chicken over (presentation side up) and add the garlic, mushrooms, juice from 1/2 lemon and wine. Stir all together. Turn heat up as high as possible and let liquids reduce until about 1/4 cup liquid remains in frypan.
Remove chicken from frypan and add the room temperature butter. Swirl it around in the frypan sauce until it is incorporated and the sauce is slightly thickened. Pour sauce over chicken and serve.