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Whole30/Paleo Potato-Leek Au Gratin I love a good, cheesy potatoes au gratin for a holiday side dish, or just a hearty side dish when entertaining; however, its 2017 and we all eat a lot healthier than that (for the most part). So, let’s transform that cheesy au gratin and make a dairy-free but still delicious Whole30/Paleo Potato-Leek Au Gratin, shall we?

Potatoes sliced oh-so thinly, filled with a delicious saute of onion and leeks, and then smothered in a delicious, creamy sauce and baked to perfection– I mean, is cheese really necessary? Not really!! I mean, it’s hard to say goodbye to cheese, I totally get it, but if you are going to go cheese-less this dish is the way to do it!

If you don’t already have a mandolin to slice the potatoes paper-thin, I recommend you getting one before the holidays! I have this one and it works great and is easy to use and store. 

So, get to slicing and make this Whole30/Paleo Potato-Leek Au Gratin for your healthy holiday menu!! Enjoy!

Potato Leek Au Gratin (Whole30/Paleo)
Serves 8
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Prep Time
20 min
Cook Time
1 hr
Prep Time
20 min
Cook Time
1 hr
  1. 3 lbs. large yellow potato
  2. 1/2 large yellow onion, sliced very thinly
  3. 2 leeks, white and light green parts, cleaned of all sand and sliced thinly
  4. 2 cloves garlic, minced
  5. 2 tbsp. olive oil
  6. 1 tbsp. ghee
  7. cooking spray
For the Sauce
  1. 2 tbsp. ghee
  2. 2 cloves garlic, minced
  3. 1 cup full fat canned, unsweetened coconut milk (be sure to blend it so that it is not separated)
  4. 1 cup chicken broth
  5. 1 tbsp. arrowroot starch
  6. salt and pepper
  7. 4 sprigs fresh thyme, leaves removed
  8. aluminum foil
  1. Preheat oven to 350 degrees.
  2. Peel the potatoes then, using a mandolin or a knife, slice the potatoes 1/8 inch thin. Set Aside.
  3. Heat 2 tbsp. olive oil and 1 tbsp. ghee in skillet over medium high heat. Add the sliced leeks and onion, 2 cloves minced garlic, and season with salt and pepper. Saute until onions are very tender, about 5-7 minutes.
  4. Combine the onion saute and the sliced potatoes in a large bowl and toss to coat evenly. Season generously with salt and pepper.
  5. Spray a casserole dish lightly with cooking spray, then spread the potato and onion mixture across the dish evenly.
  6. In a skillet, heat 2 tbsp. ghee over medium heat. Add garlic and gently fry for about 30 seconds to 1 minute, being careful not to burn. In a small bowl, combine the chicken broth with 1 tbsp. arrowroot starch, whisk until arrowroot is dissolved. Pour the chicken broth mixture into the skillet along with 1 cup coconut milk. Whisk to combine.
  7. Now add the fresh thyme leaves and some salt and pepper, to taste, and let simmer for about 5 minutes, stirring often, the sauce should thicken up a bit.
  8. Pour the sauce over the potatoes in the casserole dish. Seal tightly with foil and bake at 350 for 40 minutes. Uncover and continue to bake for 15 more minutes. When cooking time is complete, if your potatoes are not golden brown on top, turn your oven on 'broil' and broil for about 3-5 minutes, watching carefully not to burn, so that the top gets golden brown.
  9. Remove from oven and let cool for 10-15 minutes (THIS IS IMPORTANT as the sauce will thicken back up and leave you with perfect, dairy free potatoes gratin) before serving.
  10. Enjoy!
The Defined Dish

Welcome! I’m Alex.

I’m a food lover sharing healthy, simple, delicious, recipes from my kitchen to yours. Here you’ll find lots of Whole30, lots of healthy, and a little indulgence here and there because…it’s all about balance y’all!

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    1. I think it will be great. I’d do all of the steps except for bake it. Just cover with foil and refrigerate. Then just bake it the day of.

    1. Okay, you are technically right. I always thought it was considered dairy free since the milk fat/lactose was all cooked off.. appears I am wrong! My apologies!

  1. This was so good! I added cheddar cheese to half of it for my boyfriend. Truly didn’t need it! Tasted amazing on my side of the dish!