How to Make It
Place turnips, potato, apple, and bay leaf in a medium saucepan; cover with water to 2 inches above vegetable mixture. Bring to a boil; cook 10 minutes or until tender. Drain. Discard bay leaf. Return vegetable mixture to pan. Add sour cream, 1 teaspoon butter, 1/4 teaspoon salt, and 1/4 teaspoon pepper; mash to desired consistency.
Sprinkle pork evenly with 1/4 teaspoon salt and 1/4 teaspoon pepper. Place 6 tablespoons flour in a dish. Place egg in a dish. Dredge pork in flour; dip into egg. Dredge in flour.
Heat a large skillet over medium-high heat. Add 1 tablespoon oil to pan; swirl. Add 2 pork cutlets; cook 2 minutes on each side or until browned and done. Remove pork from pan; keep warm. Repeat procedure with remaining 1 tablespoon oil and 2 pork cutlets. Add stock, scraping pan to loosen browned bits. Combine remaining 5 teaspoons butter and remaining 2 tablespoons flour in a small bowl. Gradually add butter mixture to pan, stirring with a whisk. Cook 2 minutes or until thickened. Stir in remaining 1/4 teaspoon salt, 1/4 teaspoon pepper, and sage. Serve with pork and mashed vegetables.