1. Preheat oven to 350°F.
2. Lightly spray a 2-quart baking dish with oil.
3. Mix prepared potatoes with sour cream, parsley and chopped sage.
4. Blend in cheese, salt and pepper. Spread mixture into baking dish.
5. Combine breadcrumbs and Parmesan.
6. Sprinkle mixture over potatoes. Bake 20–25 minutes or until golden brown.
7. Heat olive oil in a small skillet over medium heat until hot.
8. Add sage leaves and cook 3 minutes or until crisp, stirring occasionally.
9. Transfer to paper towels and season with salt. Garnish over casserole and serve.