Easy Cheesy Ranch Au Gratin Potatoes

Thinly sliced potatoes with a creamy, cheesy ranch sauce make the perfect side dish for any night of the week. With just a few ingredients and one hour in the oven, you will have a pleasing dish that goes with just about anything and everything.

Cheesy Ranch Au Gratin Potatoes are smothered in cheese and flavored with Ranch. What’s not to love about this dish? This is definitely a comfort food that is sure to be loved by everyone. 

My family loves potatoes. We like them fried, mashed, in soups or stews, pan-fried, broiled and roasted, or in a casserole. There are so many ways to prepare potatoes, and we haven’t met a potato dish we don’t like.

This recipe is perfect for parties, get-togethers, cookouts, reunions, or weeknight meals. This is an excellent side to any grilled foods you might serve.

What is the difference between Scalloped and Au Gratin Potatoes?

Cheese is the difference between scalloped potatoes and au gratin potatoes. 

Scalloped potatoes are potatoes thinly sliced, layered, and baked in heavy cream or milk.

Au gratin Potatoes are thinly sliced potatoes that have cheese sprinkled between the layers. They are covered with a creamy sauce, topped with more cheese, and baked in the oven. 

Ingredients Needed for Creamy Scalloped Potatoes

Potatoes— I like to use russet potatoes for this recipe. I scrub them well, cut off the ends, and slice them thinly. These potatoes hold their shape and do not get mushy in this recipe. There is no need to peel the potatoes.  

Onions— Yellow onions or Vidalia onions work well for this recipe. Vidalia onions are my favorite, but if they are not in season, use yellow onions. Either onion will add a lot of flavor to this dish. Slice or dice thinly. I usually just dice them and sprinkle them on top of the layers. 

Cheese— Most of the time, I use cheddar cheese for this recipe. Although, I like to swap it and use Colby, a Mexican blend, or a combination of cheddar and pepper jack. There is no rule here; just use your favorite shredded cheese. It will be great.

Ranch–Use the dry package of Ranch Seasoning. Everything tastes better with Ranch, right?

Milk— I use whole milk for these Au gratin potatoes. That is what I always have on hand. 

Cream of Mushroom Soup— Cream of mushroom soup is my favorite, and I usually have a few cans in my pantry. 

How to Slice Potatoes for the Best Au Gratin Potatoes

Slice the potatoes as thinly as you can. I like to keep them about 1/4 of an inch to ensure the potatoes cook evenly. I eyeball the slices and do my best to make sure they are close in size.  

If you have a mandoline, this will make the slicing easier and ensure uniform slices. Personally, I just use my knife and slice as uniformly as possible. It works and gets the job done.

What is a Mandoline?

A Mandoline or sometimes spelled Mandolin is a culinary utensil used for slicing and for cutting. This kitchen gadget is super handy if you have a lot of cutting or slicing to do.

How to Make Au Gratin Potatoes from Scratch

This is a straightforward homemade au gratin potatoes recipe, and only a few simple steps are involved in making this dish a success. You don’t even need to peel the potatoes. With just a little slicing of potatoes and dicing of onions, and you are all set to assemble the scalloped potato dish. 

1. Preheat oven to 375 degrees.
2. Spray a 9″ x 13″ baking dish with nonstick spray.
3. Stir Ranch Seasoning with milk. Set aside.
4. Wash potatoes and thinly slice into 1/4″ thickness. Set aside.
5. Dice onion. Set aside.
6. Assemble: Place 1/2 of sliced potatoes in the bottom of the baking dish, slightly overlapping. Sprinkle 1/2 of the diced onions on top of the potatoes. Add 1 cup of shredded cheese to the top of the onions. Pour 1/2 cup milk/ranch over the top. 
7. Repeat layers. Potatoes, onions, cheese, and milk/ranch seasoning.
8. Top with Cream of Mushroom Soup. Spreading over the top. 
9. Cover with foil and bake at 375 degrees for 1 hour.
10. Uncover and let sit 5-10 minutes before serving.

What Are the Best Potatoes for Scalloped Potatoes? 

I recommend making these cheesy ranch potatoes with Russet potatoes. No need to peel them! I like to leave the peels on. Just be sure to wash the potatoes well and slice off the ends or any bad spots on the outside. The russet potatoes seem to work well for this recipe. They hold their shape and layer well in this dish. 

Can I Prep This Dish in Advance? 

Yes! You can assemble the cheesy ranch potatoes in advance. Follow steps 1- 9 omitting the baking. Wrap tightly in plastic wrap. Pop the dish into your refrigerator and chill up to 24 hours before baking. Take off the plastic wrap and cover with foil and bake. The potatoes may oxidize in the fridge and turn a little gray, but they will be fine once baked. 

Tips for the Best Scalloped Potatoes 

Spray a 13″ x9″ inch casserole dish with nonstick spray. This will make clean up a lot easier.

Make all slices equal thickness to ensure the potatoes cook evenly.

Prepare everything before assembling the dish. It will make the process faster. 

Slice or Dice the onions by your preference. Either way, you decide, and the outcome will be perfect.

Swap up the cheese. Use different blends such as Mexican blend, Mozzarella, cheddar, Colby, Jalapeno.

Cover with foil and bake for an hour or until the potatoes are soft.

Can I Reheat Leftover Potatoes?

Yes, you can. Heat uncovered in a 350-degree oven for about 15-20 

minutes or until hot throughout. 

Check out the following links for more potato side dishes.

Creamy Garlic Mashed Potatoes

Skillet Fried Potatoes and Onions

Hashbrown Potato Casserole

For more potato recipes, check out this post.