Potato and Celery Root Gratin
This Potato and Celery Root Gratin is my take on a baked gratin that’s taken to the next level with a combination of thinly sliced potatoes and celery root, baked in a creamy, cheese sauce. This is a truly delicious potato side dish that’s perfect for a family or holiday dinner.
Truth be told, I could honestly eat this as a meal. I’m sure many of you will agree that there’s nothing wrong with creamy, cheesy potato comfort food. Fall and winter is the perfect season for this dish.
It is the root of the celery that is hard like a carrot or parsnip and tastes just like celery.
Celery root (or celeriac) is easy to find. You may have seen it in the produce area of your supermarket and wondered what that ugly thing is (pic below). Trust me, celery root is a delicious combination with the potato; it just adds a nice, mild celery flavor.
This is a French style au gratin that is similar to scalloped potatoes. Both are baked in a milk/cream sauce, but the gratin always has some kind of cheese added.
Gratin is not limited to being made with potatoes. One of my favorite fall and winter side dishes is my Butternut Squash and Sage Gratin that has a delicious crispy panko breadcrumb topping.
My method is a little different from the traditional gratin method. I thicken the milk and add cheese before baking (basically making a cheese sauce). I find that this method avoids the curdling look that can happen from the high heat of the oven.
All potatoes! Russet, gold and even sweet potatoes will work.
How to cut thin potatoes for gratin
A mandolin on the thinnest setting is the best way. A mandoline is a great chef slicing tool for slicing anything to uniform thickness.
This depends on how thick your potato slices are. But, plan on at least 1 hour. This is why it is best to cut them as thinly as you can.