Combine flour, corn flakes, salt and pepper in separate pan (big enough to dredge chicken in)
Flatten chicken breasts to 1/4" thickness.
Dip chicken into milk mixture, then flour mixture, turning to coat
In large skillet, melt 4 Tablespoons of the butter over medium heat. Add garlic and chicken and cook until golden brown and chicken is done in the middle (4-6 min per side).
Remove chicken to a serving platter and cover with foil.
Add remaining 2 Tablespoons butter to the pan (leave the drippings in the pan as well). Stir until butter is melted, then add lemon juice, green onions and mushrooms. Continue cooking, stirring occasionally, until heated through and mushrooms are starting to brown (3-6 min).
Spoon sauce over chicken and serve immediately.
Nutrition Info Per Serving: Calories 552 Total Fat 26 g Cholesterol 287 mg Sodium 430 mg Potassium 1003 mg Total Carbohydrate 11 g Dietary Fiber 1 g Sugars 2 g Protein 65 g