Name: Vegan Cheesy Potato Casserole
Prep time: 15 min
Cook time: 35 min
Ingredients: 2 pounds russet potatoes (1/8 inch sliced and parboiled (about 3 potatoes)); 1 leek (1/8 inch sliced (reserve some slices for garnish, if desired)); 2 cloves garlic (peeled, smashed and finely minced); 1 cup cashews; 1 cup low sodium vegetable stock; 2 tablespoons apple cider vinegar; 1/4 cup nutritional yeast; 1 tablespoon tomato paste; 1 teaspoon vegan Worcestershire sauce; 1/2 teaspoon smoked paprika; 1/2 teaspoon onion powder; 1/2 teaspoon garlic powder; 1/4 teaspoon nutmeg; Sea salt and freshly ground black pepper (to taste)

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Vegan Potato Casserole features potatoes and leeks baked up in a dreamy, creamy, oil free vegan cheddar cheese sauce—made with your choice of cashews or chickpeas.

If you’ve ever loved au gratin potatoes, I think you’ll be over the moon for this cheesy potato casserole. It’s got a homemade, oil free vegan cheddar cheese sauce. None of that unhealthy store-bought stuff.

And you’ve got options here. Either go with the super rich and creamy cashew cheese version, or if nuts aren’t for you, the chickpea version (a lot like my chickpea cheese sauce recipe) is a great alternative. (Check out the nutritional info for both versions at the bottom of the page.)

I’ve tested both variations. While I personally love the more decadent cashew version, especially for a holiday dish, they’re both delicious and so satisfying.

If you haven’t tried chickpea sauces yet, check out my pasta carbonara or 5-minute Alfredo sauce. They’re quick and easy, full of fiber, low in fat, and really tasty!

How to Make This Cheesy Vegan Potato Casserole

The key to cooking this dish is getting thin, even potato slices (I used a mandoline), then pre-cooking them JUST A LITTLE so the casserole doesn’t take so long to cook. That helps keep the cheese sauce from drying out. And when you're baking up several holiday dishes, you can be sure everything will be done at the same time.

Potatoes, leek, garlic, nutritional yeast, apple cider vinegar, tomato paste, broth & spices

Potatoes, leek, garlic, nutritional yeast, apple cider vinegar, tomato paste, broth & seasonings

What You Need to Make Vegan Au Gratin Potatoes

Russet potatoes
Leek
Garlic
Cashews (raw, unsalted) or chickpeas (canned or homemade)
Nutritional yeast (I like Bragg's)
Vegan worcestershire sauce (watch out for anchovy paste)
Tomato paste
Low sodium vegetable broth (Make your own or buy boxed or powdered broth. For best results, taste it to make sure you like it before using in a recipe!)
Apple cider vinegar
Spices and seasonings (see recipe for full list)

Step-by-Step Guide to Making this Cheesy Potato Casserole

(See full recipe at the bottom of the page)

First, prep the potatoes. Get a big pot of water boiling on the stove. Peel the potatoes (if you like), then cut into ⅛” slices using a mandoline or sharp knife. Cook for 3 minutes, drain and rinse in cold water. (See expert tips below.)
Second, prep the leeks. Clean and slice them into ⅛ segments, then separate into rings. (See expert tips below.) Saute the leeks with garlic and set aside. Save some raw leek slices for garnish if desired.
Third, make the cheese sauce. Soak cashews in hot water for 15 minutes. (Or, if using chickpeas, drain and rinse them.) Add them to a blender along with the other sauce ingredients, and process until smooth and creamy.
Finally, assemble the casserole and bake. Mix the potatoes, sautéed leeks and garlic, and cheddar cheese sauce together in a bowl. Spread evenly in a 9" x 13" parchment paper-lined baking dish, top with some uncooked leek slices, cover and bake. Uncover at the end and bake 10 more minutes.

Slice the potatoes with a mandoline (or sharp knife)

Pre-cook the potato slices for 3 minutes

leek rings in a steel bowl filled with water

Fill a bowl with water to clean the leek slices

Saute the leeks and garlic

Process the cheddar cheese sauce ingredients in a blender until smooth and creamy

Cheese sauce, potato slices and leeks and garlic in a bowl

Gently toss the ingredients in a bowl, then spread evenly in a 9" x 13" baking dish

Expert Tips for Making this Recipe

To slice potatoes with a mandoline. I found the best way to do this is to first cut each potato in half, then trim 3, ⅛" slices off the tip of each potato with my knife. That gives you a flat surface to attach the vegetable holder part of the mandoline, and a flat surface on the mandoline's blade. (See picture.)
To slice potatoes with a knife. I prefer the mandoline because without thin even slices, this dish can take longer to cook and/or cook unevenly. But it is possible to do this with a very sharp knife. Just go slowly and be sure to keep checking the thickness of your potatoes so they're as close to ⅛" and even as you can get them.
Pre-cooking the potatoes. This helps the dish cook more quickly and evenly. You don't want them too soft, or they'll break apart when you toss them in the cheese sauce. It's also important to rinse them in cold water to stop the cooking (I used a colander) and be sure to pat them dry before adding to the mixing bowl so they don’t water down your sauce.
To clean the leeks. Leeks can be full of dirt and sand, and can be tricky to clean. A neat trick is to swish your leek slices around in a bowl of water. The slices will float on the top and the dirt will fall to the bottom. Then, remove the clean slices, leaving the dirt behind. (See picture.)
To slice the leeks. I can’t recommend using the mandoline, because I couldn’t figure out a way to do it safely, using the hand guard. (If you have a method, I’d love to hear it!) Use your very sharp knife and keep the slices ⅛” thick, just like the potatoes.

I’m sure ‘au gratin potatoes’ was the first French phrase I ever learned as a kid. My Mom’s favorite restaurant—a place called Charley O’s—served them in piping hot little white ramekins, broiled to lovely golden brown perfection. I swear can still taste those potatoes all these years later. Now that I’ve got this delectable vegan au gratin potatoes recipe, I can relive those memories any time.

Is there a recipe from your childhood that really takes you back? If so, drop me a note in the comment section below.

Check these holiday favorites: Vegan Porcini Mushroom Gravy, Vegan Sweet Potato Casserole, Healthy Twice-Baked Potatoes, Shepherd's Pie with Hash Brown Potatoes, Easy Vegan Collard Greens, Instant Pot Collard Greens, Shaved Brussels Sprouts with Oil Free Citrus Dressing and Healthy Brownies with Peppermint Frosting and Healthy Apple Crisp-4 Ingredients.

-Elizabeth xo

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