A delightful and creamy potato bake with a savory onion sauce and a touch of Parmesan cheese.
Preheat your oven to 350°F (175°C).
Preheating the oven ensures even cooking from the start.
In a saucepan, combine the skim milk, cornstarch, cayenne pepper, and black pepper.
Whisk continuously to avoid lumps forming in the sauce.
Cook the mixture over medium heat, stirring frequently, until it thickens and starts to bubble.
Keep stirring to prevent the sauce from sticking to the pan.
Add the chopped onion to the sauce and set aside.
Chop the onion finely for a smoother sauce texture.
Peel and thinly slice the potatoes.
Use a mandoline slicer for uniform slices.
Spray a baking dish with cooking spray and layer half of the potato slices.
Overlap the slices slightly for even cooking.
Pour half of the onion sauce over the potatoes and sprinkle with half of the Parmesan cheese.
Spread the sauce evenly to cover all the potatoes.
Layer the remaining potatoes, pour the rest of the sauce, and top with the remaining cheese.
Press down gently to compact the layers.
Cover the dish with foil and bake for 40 minutes.
Covering helps the potatoes cook through without drying out.
Remove the foil and bake for an additional 10 minutes to brown the top.
Keep an eye on it to prevent over-browning.
Let the dish rest for 5 minutes before serving.
Resting allows the layers to set for easier serving.
