“These baked brie mushrooms can be served either as an appetiser, or enjoyed as a light meal with a salad. The red onions are cooked down on a very low heat, and their sweetness balances the oozy Brie just perfectly. The general marrying of the two flavours are worth knowing, even for those that don’t like mushrooms. And, for those that LOVE the idea of a big, black mushroom – do this exact dish and top your bun-less burger with it. You will never consider a bacon and Cheddar topping again!” – Monya
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Fats of Life® is a keto and low carb recipe blog that I love to run as a hobby in my spare time. I am also the author of the best-selling Keto Kitchen Series of cookbooks. This includes my debut best-seller Keto Kitchen (2020). The fun and exciting Lazy Keto Kitchen (2021). And, the clever and inspiring Budget Keto Kitchen (2022). My 4th cookbook, Quick Keto Kitchen (2023) is as fantastic as the first three, and packed with spectacular, easy creations!
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The links above will take you to Amazon UK. For USA and other countries, see the global Amazon links here: Keto Kitchen ; Lazy Keto Kitchen ; Budget Keto Kitchen ; Quick Keto Kitchen.
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More on Brie Mushrooms with Red Onion Chutney…
The keto diet, known for its low-carb, high-fat approach, has transformed the way people think about food. While it may seem challenging to find delicious and satisfying keto-friendly dishes, this little meal offers a delectable solution.

FOLLOW MONYA:
Portobello mushrooms serve as the perfect canvas for this keto-friendly masterpiece. These hearty fungi are not only low in carbohydrates but also packed with essential nutrients and fibre. Filling them with rich, creamy Brie cheese adds a luxurious texture and flavour that satisfies the palate while adhering to keto principles.
The magic of this dish doesn’t stop there. Cooked-down red onions provide a sweet contrast that elevates the overall experience. Red onions, when caramelized, become a low-carb source of natural sweetness that complements the earthiness of the Portobello mushrooms and the creaminess of the Brie cheese.
So, whether you’re a committed keto enthusiast or simply looking for a delicious, low-carb meal, these mushrooms are a mouthwatering option that showcases the versatility and creativity of keto cuisine.

It is important to note that to maintain ketosis, it’s essential to track carbohydrate intake and ensure it aligns with your daily macro goals. Consulting with a healthcare professional is advised before making significant dietary changes. Scroll to the bottom to see the full macros and allergens for these Brie Mushrooms with Red Onion Chutney, as well as all the Light Meals & Appetisers on Fats of Life®.
Brie Mushrooms with Red Onion Chutney
Per serving
Ingredients
- 2 tsp unsalted butter
- 1 red onion, peeled and sliced
- 1 TB red wine vinegar
- 5 large portobello mushrooms
- truffle-infused olive oil
- 150 g (5.3 oz) ripe good-quality brie, sliced
- fresh thyme, leaves picked
- pink Himalayan salt
Instructions
- Heat the butter in a small pan and gently cook the onions over moderate heat until completely softened. Add the vinegar to deglaze the pan and reduce the heat to very low to continue to cook them until jammy and all the vinegar has evaporated. Set aside to keep warm.
- In the meantime, preheat the oven to 180°C (fan oven). This is 200°C for conventional ovens (or 400°F / gas mark 6).
- Wipe the mushrooms clean and gently remove and discard the stalk without damaging the mushroom.
- Place the mushrooms on a roasting tray and brush with a very small amount of truffle-infused olive oil. Place in the oven for 7 minutes, then remove the tray from the oven. Using a spatula and some kitchen paper, tip each mushroom at an angle to drain any liquid.
- Divide the sliced Brie between the ‘shrooms and return the tray to the oven for 5 minutes, or until you can see the cheese has melted into a gooey mess.
- Remove the grilled brie baked mushrooms from the tray using a spatula (I advise tipping it slightly again to allow excess moisture to run off) and serve with the onion chutney. Garnish with picked thyme leaves and finish with small scatter of Pink Himalayan Salt.

My name is Monya Kilian Palmer. If you loved this recipe, please follow and tag me @mkilianpalmer on Instagram so we can all see your lovely creations!
Nutritional Information per ‘shroomCalories 175Kcal / 732kJ
Fat 14g
Carbohydrates 4.5g
Protein 8.1g
Allergens
Milk
Sulphites
See all the Light Meals / Appetisers on Fats of Life:






Disclaimer: The nutritional analysis, macro and allergen breakdown of the recipes on this site have been manually and carefully calculated using the cloud-based software NUTRITICS®. NUTRITICS® is fully approved by the relevant Trading Standards organizations and is EU and FDA-compliant. The macro calculations are provided as a courtesy to you based on the author's weighing of ingredients when creating the dishes. If Erythritol (a sugar polyol) has been used in any of the recipes, it has already been manually excluded from the final carbohydrate count. The author is a chef - not a medical professional - and this website has been designed to provide you with recipe ideas to suit the low carb lifestyle you have discussed with your GP.





1 Comment
Drop me a line if you have any questions or comments about this recipe. I will do my best to reply as soon as possible! Monya xxx