Stuffed onions make a fabulous keto side dish — when you drop the carby breadcrumbs used in the traditional recipes and add tasty, full-fat ingredients like heavy cream, extra virgin olive oil, and Parmesan. Onions release their naturally sweet flavors when cooked, and when you include some herbs to complement the flavors, you’ll get a super-flavorful side that’s worth raving about!
How to make the Stuffed Onions
Let’s admit: this is not the easiest recipe in the world, but it certainly is simple and very tasty — well worth the effort. After all, this dish is not too laborious to make, I think removing the center layers from the onions – and chopping them – is the most time-consuming part. I prefer to use a knife to cut off a small part of the center of the onion and then just grab with fingers the center layers until I have about 1/2-inch (1.2 cm) thick “walls.” Basically, you can just grab and remove the center layers of the onions with your fingers — it finally doesn’t matter if you remove the whole center and make the onion completely hollow — not leaving any flesh to the bottom so that the onion would make a cup for the stuffing (boy, that was difficult to explain, and I think I still didn’t manage to make it clear… but I hope you understand. It’s always tricky to try to explain something when you are not a native speaker of that language.)
In any case, it’s a good idea to remove enough center, as you really want to add as much of the tasty filling as you can. Moreover, removing most of the center and leaving just thinnish walls is also a great way to reduce carbs, as onion does have some carbs, and if you remove the center, you also remove those carbs — filling the empty space with less carby stuff like cream and Parmesan. (For more ideas how to reduce carbs further, check the How to get some variation to the Stuffed Onion recipe section later in this post).
Since this recipe makes just 4 servings, you can naturally make a bigger batch at once — when you are at it — and freeze the leftover stuffed onions for later use.
But let’s take a look at how to prepare this superb dish:
Preheat the oven to 350 °F (175 °C).
Take 4 medium-sized onions. Peel them.
Cut off a small slice from the bottom of each onion so that the onions stand straight.
Take a medium to large saucepan and place the onions in the saucepan so that they stand straight. (To be honest, I really don’t know if it matters if they stand straight or not. Just place them into a saucepan, and don’t worry!)
Pour some boiling water over the onions so that 1 inch (2.5 cm) of the bottom of the saucepan is covered with water.
Cook, covered, for about 15 minutes…
…or until the onions are soft.
Remove the onions from the hot water. (When shooting the video, I realized there’s a better technique for this, so please check the video in this post how to handle the onions!)
Discard the water. Let the onions cool until you can handle them.
Cut about 1/2-inch (1.2 cm) slice off the top of each onion.
Remove the center of each onion, leaving about 1/2-inch (1.2 cm) shell to the edges.
Chop the removed centers finely. Set aside.
Heat a skillet over medium-high heat. Add 2 tablespoons extra virgin olive oil…
…1 teaspoon dried thyme…
…the chopped onion centers…
…and 1/3 cup (80 ml) heavy cream in the skillet.
Cook, all the time stirring…
…until very thick, about 10 minutes.
Remove from the heat. Add 1 cup (240 ml) grated Parmesan…
…and mix until well combined. Looks cheeeeesy!
Place the hollowed onions into a shallow baking dish.
Stuff the onions with the creamy Parmesan mixture.
Bake in the preheated oven for about 25-30 minutes, or until the stuffing is set and golden on top.
Remove from the oven.
…sprinkle some fresh thyme on top if wished, and serve.
How I came up with this recipe
Making stuffed onions has been very long on my list. I’ve never really made them — as long as I remember — but the idea sounded so intriguing that I wanted to try to make stuffed onions one day.
That one day took long to happen. Besides, I had too many ideas with what to fill the onions. I simply couldn’t make a decision which ingredients to use! Finally, I decided to take a simple way (I’m all about simple…) and make Italian-style filling with chopped onion (that is, the removed center parts of the onions), Parmesan, and a herb. For that herb, I was first thinking of rosemary, but then chose thyme — just because I like thyme more than rosemary! Well, of course, there exist numerous herb varieties in this world, but somehow, I concluded thyme would be just perfect with Parmesan and onions.
I was afraid the filling turns out too dry if I use just onion and Parmesan. There has to be something to bind the ingredients and make the filling more like a succulent sauce rather than a dry and crumbly mixture of stuff.
Aha! Now I knew: I needed heavy cream. Very often, I use heavy cream for sauces. I simply cook the cream until it has reduced into a thick sauce. Like that, you don’t need any thickeners. Maybe the same method would work for the filling for the stuffed onions — making it rich and creamy? And if I fry the chopped onion in olive oil, I get incorporated even more tasty fat to the dish.
After pondering the amounts, I simply started experimenting. I had seen many stuffed onion recipes in the past, and based on those, chose my way to prepare the dish.
First, I cooked 4 peeled onions until they were soft. Like this, the core would be easier to remove than from raw onions. And you wouldn’t need that long baking time when the onions were already soft.
When the cooked onions were cooled a bit so that I would handle them, I removed the center parts and placed the hollowed onions onto a baking dish. I chopped the center parts finely.
Next, I heated a skillet over medium-high heat and added 2 tablespoons extra virgin olive oil. I was actually prepared to add 1/4 cup (60 ml) olive oil, but already 2 tablespoons felt a lot, so I decided not to add more at that point. I also added 1 teaspoon dried thyme, the chopped onion centers — and finally 1/3 cup (80 ml) cream based on my gut feeling.
I cooked the mixture until it had reduced into a thick sauce. It looked just what I was after: thick yet succulent. But I still wanted to add some Parmesan to bring in more flavor and richness. Well, which savory dish wouldn’t benefit from some cheese, anyway? I took 1 cup (240 ml) freshly-grated Parmesan and mixed it well with the sauce.
The Parmesan melted beautifully into the sauce — that was now both creamy and cheesy. Yum!
I filled the onions with the creamy Parmesan and onion mixture. There was plenty of filling still left. Now what?
I added two eggs and made scrambled eggs for lunch for myself. What a great and tasty way to use the leftover filling! The dish was very delicious — so I was really looking forward to the stuffed onions. With this tasty sauce, nothing can go wrong (at least I hoped!). Here’s my scrambled eggs (sorry, the photo doesn’t do justice to the delicious taste of the dish!):
I baked the stuffed onions for 25 minutes. I was actually prepared to bake them longer, but as they looked just perfect after 25 minutes in my partially-broken oven, I decided to remove them from the oven and see how they looked and tasted — and if the stuffing had cooked through.
It was cooked through, and the onions were unbelievably delicious! Well, my son didn’t want to taste them, but my husband was raving about them. And I totally loved them, too.
Later, when conducting further experiments, I noticed that I didn’t remove enough core from some of the onions. Like that, there was not enough filling but just too much plain onion. Lesson learned: remove enough core to get more of that lovely filling!
Here’s the recipe for you to enjoy:
- 4 medium onions
- 2 tablespoons extra virgin olive oil
- 1 teaspoon dried thyme
- 1/3 cup = 80 ml heavy cream
- 1 cup = 240 ml freshly grated Parmesan cheese
- Preheat the oven to 350 °F (175 °C).
- Peel the onions. Cut off a small slice from the bottom of each onion so that the onions stand straight. Take a medium to large saucepan and place the onions in the saucepan.
- Pour some boiling water over the onions so that 1 inch (2.5 cm) of the bottom of the saucepan is covered with water. Cook, covered, for about 15 minutes, or until the onions are soft.
- Remove the onions from the hot water. Discard the water. Let the onions cool down until you can handle them.
- Cut about 1/2-inch (1.2 cm) slice off the top of each onion. Remove the center of each onion, leaving about 1/2-inch (1.2 cm) shell to the edges.
- Chop the removed centers finely.
- Heat a skillet over medium-high heat. Place the olive oil, thyme, chopped onion centers, and the heavy cream in the skillet.
- Cook, all the time, stirring, until very thick, about 10 minutes.
- Remove from the heat. Add the grated Parmesan and mix until well combined.
- Place the hollowed onions into a shallow baking dish. Stuff the onions with the creamy Parmesan mixture.
- Bake in the preheated oven for about 25 minutes, or until the stuffing is set and golden in color.
- Remove from the oven, sprinkle some fresh thyme on top if wished, and serve.
|Nutrition information||In total||Per serving if 4 servings in total|
|Protein||8.5 g||2.1 g|
|Fat||40.8 g||10.2 g|
|Net carbs||13.5 g||3.4 g|
|kcal||460 kcal||115 kcal|
How to get some variation to the Stuffed Onion recipe
I bet some of you are thinking, “but this recipe cries for bacon!” — and you can certainly add some fried and crumbled bacon to this recipe. Actually, I was first planning to add some bacon, too, but then decided to keep the recipe simple and just mention the bacon here as an optional ingredient.
Naturally, you can use different herbs — not just thyme – for this dish. For example, rosemary and oregano, even mint, go well with onion and accompany this rich dish, balancing out the greasiness. Feel free to add some crushed garlic as well. Would there be any savory dish which wouldn’t benefit from some garlic (or that cheese!). By the way, there used to be a restaurant in Helsinki that put garlic in desserts, too…
And if you still want to reduce the carbs further, use the chopped cores of the onions for another dish, and add, for example, a meaty and cheesy zero-carb filling to the hollowed onions. I’m mainly thinking of bulk sausage or ground beef — you can certainly make a thick sauce of those with heavy cream. I often do that, and I actually have a couple of recipes for those kinds of sauces in my books as well.
Feel free to switch the Parmesan to other type of cheese. Swiss cheese and feta are also flavorful cheese varieties and they work great in this dish.
Last Sunday, I was talking at Minä Olen expo in Helsinki at Finlandia Hall. I was so honored to speak on the same stage I had been listening to Kraftwerk quite precisely two years ago! I don’t know if there are any photos about my talk, but there is a video where Karita Aaltonen — also a famous author, presenter, and life coach — is introducing me and when I start my talk (video by Olli Kolehmainen):
Here’s the Sunday’s program for the big auditorium in Finlandia Hall:
I did some edits for my upcoming keto book in Bistro Naapuri — a nice place in the center of Tampere. They were serving this wonderful keto chocolate cake. It’s the only place in Finland I’ve found to serve decent sweet keto stuff!
On Friday, on Valentine’s Day, I was pampering my family with this keto Valentine’s Day cake that you might have seen on Instagram as well:
Here in Finland, Valentine’s Day is more like a friendship day rather than a romantic day for couples. Actually, we call Valentine’s Day “ystävänpäivä”, which indeed means “friend’s day”. I feel so privileged and grateful: I have wonderful friends, amazing colleagues, the best husband, and the most adorable son — many reasons to celebrate!
How did you celebrate your Valentine’s Day? Hopefully, with delicious keto treats and warm feelings with your loved ones!
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