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Low-Carb "Potato" Gratin

Potato Gratin, also known as Potato Dauphinoise is one of the meals I didn't want to give up when I started following a low-carb diet. When looking for a keto alternative, I spent quite some time trying to figure out what works best instead of potatoes.

Cauliflower was the first substitute I tried but wasn't happy with the result. There is a better ingredient for making low-carb potato gratin - rutabaga, also known as swede. Although rutabaga contains more carbs than cauliflower, in my opinion it's worth using it in this recipe.

I've been using this amazing low-carb vegetable for years - mostly in soups and stews like this one. It has proven to work even for keto fries and makes the best potato salad - a traditional Czech Christmas side dish that is served with breadcrumbed fried fish.

You could try other vegetables too - kohlrabi or turnips are also good options. Just for a comparison (per 100 grams / 3.5 ounces):

  • white potatoes - 13.3 g net carbs (15.7 g total carbs)
  • sweet potatoes - 17.2 g net carbs (20.3 g total carbs)
  • turnips - 4.6 g net carbs (6.4 g total carbs)
  • rutabaga / swede - 6.3 g net carbs (8.6 g total carbs)
  • cauliflower - 3 g net carbs (5 g total carbs)
  • kohlrabi - 2.6 g net carbs (6.2 g total carbs)
  • celery root - 7 g net carbs (9 g total carbs)
  • radishes - 1.8 g net carbs (3.4 g total carbs)
  • daikon radish - 4 g net carbs (6 g total carbs)
  • parsley roots - 1.7 g net carbs (3.5 g total carbs)

Since it's the Holiday season, make sure you check out my festive keto recipes!

Preparation time


Nutritional values (per serving):

10.2 grams 3 grams 13.9 grams 37.7 grams 21.4 grams 445 calories
Total Carbs13.2grams
Net Carbs10.2grams
of which Saturated21.4grams
Magnesium44(11% RDA)
Potassium622(31% EMR)

Macronutrient ratio: Calories from carbs (9%), protein (13%), fat (78%)

Ingredients (makes 8 servings):

  • 1 kg rutabaga, about 2 large pieces (2.2 lb)
  • 3 tbsp ghee or lard (45 g/ 1.6 oz)
  • 1 small white onion (70 g/ 2.5 oz)
  • 8 large slices bacon (240 g/ 8.5 oz)
  • 1-2 tbsp freshly chopped thyme or 1-2 tsp dried thyme
  • 1 cup heavy whipping ream (240 ml / 8 fl oz)
  • 3 cups chicken stock, vegetable stock or bone broth (720 ml/ 24 fl oz)
  • 1 cup grated cheddar cheese (110 g/ 4 oz)
  • 1 tsp salt or more to taste (I like pink Himalayan)
  • freshly ground black pepper
  • ½ cup creme fraiche or sour cream (120 g/ 4.2 oz)
  • ½ cup grated Parmesan cheese (45 g/ 1.6 oz)


  1. Preheat the oven to 160 C / 320 F. Peel and slice the onion and place in a hot pan greased with ghee. Cook over a medium heat until fragrant for about 5 minutes while stirring.
  2. Slice the bacon and add to the pan with the onion. Add thyme and cook until the bacon is lightly browned from all sides. Take off the heat and set aside.
  3. Meanwhile, peel and halve the rutabaga. Cut thinly, into about ¼ cm (⅛ inch) slices.
    Tip: if you want to reduce the baking time, to just about 45 minutes, pre-cook the rutabaga. Place in a pot filled with water and cook for about 10 minutes. Then, drain and use as described in the following steps.
  4. There will be three layers of rutabaga. Place the first layer of slices into a large baking dish greased with some ghee. Top with half of the bacon and onion mixture ...
  5. ... and half of the grated cheddar cheese. Top with another layer of rutabaga slices, bacon, onion and grated cheddar. Finally, top with the last layer of rutabaga slices. In a bowl, combine the cream, chicken stock, salt and pepper.
  6. Pour into the baking dish over the rutabaga until almost covered. If needed, add some more chicken stock. Season with more salt and pepper to taste. You can use one large baking dish or a single-serving baking dish like this one from Le Creuset.
  7. Cover with aluminum foil and transfer into the oven over a baking dish to collect any juices dripping from the aluminum cover. Bake covered for an hour.
    After an hour, the rutabaga will get softer. Remove the aluminum foil and press the rutabaga down with a spatula to submerge it into the cream mixture and prevent it from drying. Bake for another 45-60 minutes or until the rutabaga gets tender, pressing it down with a spatula every 15 minutes. When done, remove from the oven and set aside. Turn the oven up to 200 C / 400 F.
  8. Spread the creme fraiche and grated parmesan cheese on top.
  9. Place back in the oven for another 20-30 minutes or until the cheese is melted and the top is crispy and golden brown.
    I baked mine a day ahead, let it chill and stored in the fridge to set. Then I made the final browning just before serving. This way if wasn't burning hot, was perfectly set and ready to be served straight from the oven. Serve as a side with meat or fish, or as a light lunch - by itself with some crispy greens. It tastes great both hot and cold. Enjoy!

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Please, note that I do not offer personalised advice. For personalised advice you can contact one of our experts.

Comments (8)

I made this with turnips (I bought them by accident because they LOOK THE SAME!I knew as soon as I started peeling they were turnips) anyway,  it was good.  Paired really well with salmon.


Turnips are great and contain less carbs so it was a good swap Wink


Have you any experience with jicama? I remember eating it as a raw vegetable years ago---it's crunchy when raw, without much flavor, not sweet, somewhat similar to white potato. It's also very low glycemic load, so I thought it might be useful in stews, gratins and so on.


That may work too! I wish I could get it where I live. We don't seem to have jicama in the UK...


What do you think about using celery root in this recipe?


Good point, I've added celeriac to the list, yes it will work too Smile


It seems the kind of comfort food perfect for a cold winter! If only I could find rutabaga here! What about topinambour? You did not mention it, though it works finely in potatoes' recipes.
Thank you


It is! Jerusalem artichoke (topinambour) has more carbs than white potatoes - it's closer to sweet potatoes. So if you don't mind that I think it will work Smile


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