Whether you’re baking a cheesy potato casserole, a stuffed baked potato casserole, or any other recipe that uses the very versatile potato, you need to precook it first. You may have skipped this step in the past because you weren’t sure what parboiling really is. Well, it’s exactly what the name suggests: partially cooking something. Per Our everyday lifeParboiling potatoes is an essential step in baking. Otherwise, it takes an inordinate amount of time to achieve the desired softness and tenderness that is the hallmark of a quality cooked potato.
If you use raw potatoes in your casserole, they will cook in the oven, but the result will be different than if you cooked them first. Since they’re partially cooked when they’re cooked, the oven simply works to soften and juicy (or crispy, depending on the recipe). If they are added raw, the time spent in the oven is used only for cooking.
So if you want a crispy potato crust, parboiling your spuds is the way to go. You’ll see why it’s so important when you don’t and end up eating a bite of overcooked veggies and undercooked potatoes. Plus, parboiling speeds up the overall cooking time, allowing your potatoes to cook in the same timeframe as the other veggies in your casserole.