Turnips Gratin – the Keto “Potatoes” Gratin

Keto “Potatoes” Gratin – or rather – how I learned to love turnips. That’s right, turnips. This member of the radish family is as low carb as they come and are incredibly close to real potatoes in both texture and flavor when used in dishes. This recipe is both incredibly easy and absolutely delicious so much so that every time I’ve made it, everyone asks for seconds (and thirds, if there is any left).

Although I’ve used turnips as a potato replacement, like in the Caldo Gallego, I never thought I would use this little root for my favorite holiday side dish: “potatoes” au gratin. The incredible part is, I think it may actually be better than potatoes! Although there are a variety of ingredients such as jicama and rutabaga that are noteworthy – the turnips, really steal the show.

Delicious Turnip Gratin - Black Tie Kitchen
Delicious Turnip Gratin – Black Tie Kitchen

What’s the difference between scalloped potatoes and potatoes gratin? (or scalloped turnips vs turnips gratin)

Often times, these two terms get used interchangeably, but there is a difference: cheese. Potatoes gratin have cheese in the dish – usually between the layers and as a topping, whereas scalloped potatoes do not. That’s literally it. There is some slight nuance though – scalloped potatoes tend to be sliced a little thicker as opposed to au gratin, where we want to slice them super thin!

Turnips sliced thin - Black Tie Kitchen
Turnips sliced thin – Black Tie Kitchen

Do you really need a mandolin?

If you want superb turnips gratin – you need a mandolin. Mandolins will slice your turnip the same thickness all the time, every time. This is crucial as different thickness slices will lead to vastly different cook times, inconsistent texture, and just an overall unpleasantness to the dish. However, if you don’t have a mandolin and don’t care to purchase one, you can use a sharp knife and attempt to cut the slices the same thickness. Just be forewarned that it may not turn out as well… just know that I warned you.

Safety, safety, safety

It may seem like a joke, but mandolins are dangerous. Yes, dangerous. This seemingly dull blade attached to a board may seem the least threatening tool in your kitchen, but everyone I know – including myself – has sliced their finger when using a mandolin. *GRAPHIC WARNING* We all think we are kitchen superheroes until we’re trying to find the slice of our finger inside the potatoes and attempting not to get blood everywhere while holding your hand above your head to control the bleeding. It’s literally happened to everyone I know who has ever used a mandolin.

That said, I highly recommend you throw away whatever safety holder nonsense came with your mandolin and instead, purchase one of the cut-resistant gloves that are used in food prep and professional kitchens. It allows you to have much better control over the ingredient in your hand, gives you piece of mind on your protection, and best of all, are relatively cheap. I used to think they were stupid until I used one – I know keep a pair stowed away in a kitchen drawer for when the mandolin comes out or I have some cutting that requires tricky knife work.

How much cream do I add between layers?

When you’re layering the turnips, you may be tempted to pour a lot of the cream in between – don’t. We just want to provide a little moisture at the moment. Anything extra will be added at the end when we pour any remainder in!

Drizzled cream over the turnips - Black Tie Kitchen
Drizzled cream over the turnips, just a little bit is needed!

What do I do with the thyme and garlic?

Once you pour the remaining cream into the dish, you can use the thyme and garlic for something else, or simply throw it away. You could add it to a little olive oil and eat with bread (if you’re not doing low-carb). For the spices that will be at the bottom of the pan, I always like to pour add them over the top of the turnips as they will carry the flavor and also hide like a flavor bomb underneath the cheesy crust!

Add Remaining Cream - Black Tie Kitchen
Add Remaining Cream and discard the aromatics – Black Tie Kitchen
Cooked Turnip Gratin - Black Tie Kitchen

Turnips Gratin

Yield: 6 servings
Prep Time: 15 minutes
Cook Time: 40 minutes
Total Time: 55 minutes

Turnips gratin a a delicious side dish that rivals potatoes gratin. Rich, a hint of sweet, and aromatic - this dish is easy to make and sure to have everyone asking for seconds.


  • 2 cups heavy cream
  • 5-8 sprigs of thyme
  • 4-5 garlic cloves
  • 1/2 tsp black pepper
  • 1/2 tsp salt
  • 1/2 tsp nutmeg
  • 4-5 medium sized turnips
  • Parmesan Cheese
  • 2-6 ounces Gruyere cheese (or mild cheddar)
  • butter (for greasing the pan)



  1. Peel and smash your garlic. Then add them to a small sauce pot. No need to be fancy here as it won't make it to the final dish!
  2. To the same sauce pot, add your heavy cream, salt, black pepper, thyme, and nutmeg.
  3. Place the pot on the stovetop over low heat - we dont want it to boil or simmer. We simply want to infuse the cream with the flavors and aromatics.
  4. Pre-heat the oven to 375°F/190°C
  5. Remove any greens if present and Peel your turnips*
  6. Using a mandolin slicer, set the cut slice size as thin as possible and begin to slice your turnips. You could cut the turnip on its side of flat - one yields very large slices while the other yields smaller, but more oblong slices. There is no noticeable difference in cut direction regarding texture. (Please see notes for safety!)**
  7. Check on the cream to ensure the mixture is heating up. Give it a taste and adjust accordingly - if it doesn't taste like heaven to you add more of whichever spice it needs!
  8. Using some butter, rub down the casserole dish to give it a nice thin coat. To do it well, you'll have to use your finger and ensure the sides are covered well!
  9. Using your sliced turnips, place a single layer on the bottom of the casserole dish, slightly overlapping each piece as you progress so that the casserole dish is no longer visible.
  10. Remove the cream mixture from the stovetop, and throw away the thyme sprigs (they'll just get in the way). Using a spoon, lightly pour a small drizzle over the rows of layered turnip slices. It should seem very little - but we simply want some moisture and flavor between each later. Avoid adding the garlic.
  11. Grate some parmesan cheese over the layer. You could also add some gruyere or cheddar cheese if you want something incredibly cheesy.
  12. Again, layer more turnips, drizzle some cream mixture, parmesan cheese, (optional additional cheese), and repeat until you get to the top. Pour any of the remaining mixture (withholding the garlic) over the casserole dish. Grate some more fresh parmesan and also give it a nice healthy topping of gruyere cheese - this will give it that nice crust on top!
  13. Place into the oven and bake for 30 minutes, then continue cooking in 5 minute intervals until the top becomes the desired golden color!
  14. Remove from the oven, slice, and enjoy!


* Turnip greens can be cooked just like collard greens or spinach! Don't throw them away!

** SAFETY is critical with a mandolin. Use a kevlar glove or the mandolin's safety holder. Don't think you're special - we all thought the same until we lost a part of our finger!

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Nutrition Information
Serving Size 1/6th
Amount Per Serving Calories 391Total Fat 33.7gSaturated Fat 22.6gCarbohydrates 13.5gFiber 2gSugar 4gProtein 7.6g

- The carb count can be made lower by using heavy cream with 0 carbs - If you don't have thyme, you can also use rosemary

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Cooked Turnip Gratin - Black Tie Kitchen

This Post Has 15 Comments

  1. Thomas Bilbo (He/Him/Hobbit)

    OK… what’s not to love about this, brown cheesy goodness, with a root vegetable.

    Thanks for sharing!

  2. Nancy

    11.5 net carbs is crapload for one serving!! However, since the Holiday Meal is generally the only one of the day, I shall make an exception. Carry on.

    1. Dennis

      I usually calculate the carbs for the heavy cream (as some have 1g while others have 0) – that makes a pretty significant difference in this recipe as it’s high in cream! Turnips also tend to have about 4-6g of carbs in them, so it’s not no-carb, but it’s way lower than potatoes. It’s one of those ‘I can have this or I can have that – either way Im having one of them…” 😂

      1. DvDelf

        2 cups of Heavy Whipping Cream, which has a higher fat content than Heavy Cream still will have about 13 net carbs for the 2 cups. Just because the label states 0 carbs for a serving( 1 Tbsp) anything under 1 can be shown as 0 according to FDA labeling guidelines. I made this mistake early on in my Keto journey. Now I count those carbs. BTW : your site is my go to for anything keto cooking, and your videos are a delight!

        1. Dennis

          It’s why I count the carbs in the nutrition!

  3. Kinga

    Tempted to try this with Jicama. Keep up the good work.

    1. Dennis

      It will pretty much work with any root vegetable, you’ll just have to adjust liquid and cooking times to get it right!

    1. Dennis

      Will have to check it out! thanks!

  4. Barbara

    Hi. We tried this for dinner last night, thanksgiving, and it tasted wonderful. But, our dish had an excessive amount of liquid. We followed the recipe to the letter. What could have been the problem? I need your science skills to prevent this from happening again. Thanks.

    1. Dennis

      Barbara! Sorry for the late reply! You can just cook it longer! That’s where the different freshness of turnips comes into play and such. If it’s too watery, just pop it back into the oven. For example, there were some viewers who tried it with rutabaga (i.e. yellow turnips) and it came out dry – so they had to add an extra half cup of cream, to which they said it was fantastic!

  5. Holly H

    I made this exactly as directed and it’s amazing, dangerous even. ❤

    1. Dennis

      haha I know right?! Glad you enjoyed it =)

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