Potato and Mushroom Gratin with Brie

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I feel the need to remind you that the ugliest food is often the tastiest – and this potato and mushroom gratin is the perfect example. It’s no looker, but my word, the flavours are unreal! Buttery garlic mushrooms, melt-in-your-mouth slices of potato, an ultra luxurious cream sauce, and slices of gooey brie that get a little caramelised on the edges… seriously, I beg you not to judge this mushroom gratin on its appearance!

Mushroom and potato gratin in a bowl topped with fresh parsley.

This potato and mushroom gratin makes the perfect luxurious side dish – it’s like potato dauphinoise meets creamy garlic mushrooms, all baked up in one bubbly pan.

Serve this mushroom gratin alongside your favourite vegetarian protein, and plenty of extra veggies – just don’t bother going to too much effort with your other dishes, as this gratin will inevitably be the highlight of your plate regardless!

❤️ Why You’ll Love This Recipe

  • The flavours! Oh my… the flavours.
  • It reheats beautifully, so if you can resist eating it all in one sitting, you’ll be glad to have leftovers.
  • A special side dish like this mushroom gratin really takes a simple meal up a notch.
  • It’s easy to make, but extraordinary enough to serve for a special occasion, like Thanksgiving or Christmas.

🥗 Ingredients

Here’s what you’ll need to make this recipe. You’ll also need a few cupboard staples, like oil and black pepper. See the printable recipe card below for detailed ingredient quantities.

Ingredients for mushroom and potato gratin with text overlay.
  • mushrooms
  • potatoes
  • brie cheese
  • cream
  • fresh parsley (just to garnish)
  • vegetable stock – or just use salt if you prefer!
  • garlic – I used minced garlic from a jar, but feel free to use fresh garlic if you prefer.
  • dried thyme
  • nutmeg

Becca’s Top Tip

I used a few different kinds of mushrooms – baby portobellos, chestnut mushrooms, and button mushrooms. It looks quite nice to have different sizes and shapes, but you can definitely stick to just one type of mushroom if you prefer!

📋 Instructions

Here’s how to make this recipe – see below for the printable recipe with detailed ingredients and instructions.

Sliced mushrooms cooking in a frying pan in a cream sauce.

Step 1: Cook mushrooms with plenty of garlic in a buttery cream sauce.

Thinly slices potatoes on a chopping board.

Step 2: Peel some potatoes and slice them as thinly as you can.

Collage showing sliced potatoes, garlic mushrooms and brie being layered in a baking dish.

Step 3: In a baking dish, layer up the sliced potatoes, creamy garlic mushrooms, and slices of brie.

Potato and mushroom bake in a dish topped with crispy brie.

Step 4: Bake until the potatoes are soft and the brie on top is golden brown and crispy.

Becca’s Top Tip

If you’re not a fan of brie, you could easily swap it for some grated cheddar cheese instead.

💭 Recipe FAQs

Can I prepare this dish in advance?

Yes – just layer the ingredients in the baking dish, then store in the fridge until you’re ready to bake and serve. If you’re baking the dish when it’s cold from the fridge, don’t preheat the oven – just place the dish in a cold oven and let them warm up gradually together.

How should I store any leftovers?

Leftover mushroom gratin should be stored in an airtight tub in the fridge for around 3 days.

How can I reheat any leftovers?

I would reheat leftover potato gratin in the microwave, as it’s quick and easy, and won’t cause the dish to dry out.

Creamy potato and mushroom gratin with brie in a baking dish, with a scoop removed.
Creamy mushroom and potato gratin in a dish being scooped with a spoon.

Potato and Mushroom Gratin with Brie

An ultra luxurious potato and mushroom gratin with caramelised brie – like potato dauphinoise but a million times better!

If you’ve cooked this recipe, don’t forget to leave a star rating!

5 from 4 votes
Print Pin Comment
Prep Time: 25 minutes
Cook Time: 1 hour 10 minutes
Total Time: 1 hour 35 minutes
Servings: 4 people
Calories: 355kcal
Author: Becca Heyes


  • 1 Tablespoon oil
  • 350 g (~ 3/4 lb) mushrooms, thinly sliced (I used a mixture of chestnut, baby portobello, and button)
  • 1 teaspoon minced garlic
  • 1/2 teaspoon dried thyme
  • 1/2 teaspoon black pepper
  • 1/4 teaspoon ground nutmeg
  • 1/2 vegetable stock cube, crumbled
  • 450 g (~ 1 lb) potatoes
  • 1 Tablespoon butter
  • 250 ml (~ 1 cup) cream (I used single cream)
  • 200 g (~ 7 oz) brie, sliced
  • Fresh parsley, to serve (optional)


  • Heat a dash of oil in a deep frying pan, and add the sliced mushrooms. Cook over a medium heat for around 5 minutes, stirring regularly, until fairly soft. Add the next 5 ingredients (garlic through stock cube), and cook for a few more minutes.
  • While the mushrooms are cooking, peel the potatoes and slice them very thinly. If you have a mandoline, you can use that – otherwise, just use a large knife.
  • Add the butter and cream to the pan with the mushrooms, and bring to a gentle simmer for a minute or two, until the butter has melted and the ingredients are well combined.
  • To assemble the mushroom gratin, layer up the creamy mushrooms with the sliced potatoes and the sliced brie. My baking dish measured approximately 8 x 8 inches. The exact order of your layers doesn't matter too much, but here's how I layered mine:
    – 1 or 2 tablespoons of cream spread around the bottom of the dish, to avoid sticking
    – 1/3 of the sliced potatoes
    – 1/2 of the creamy mushrooms
    – Another 1/3 of the potatoes
    – 1/2 of the brie
    – The final 1/3 of the potatoes
    – The remaining 1/2 of the creamy mushrooms
    – The remaining 1/2 of the brie
  • Drizzle any remaining cream over the dish, trying to cover any potato edges that are exposed.
  • Cover the dish with a lid or some kitchen foil, and bake at 190°C (Gas Mark 5 / 375°F) for around an hour, or until the potato slices are completely soft. If you'd like to crisp up the topping a little, remove the lid, and return to the oven for a further 10 minutes, or until crisped up to your liking.
  • If you want to, garnish with fresh parsley before serving.


Nutrition Facts
Potato and Mushroom Gratin with Brie
Amount Per Serving (1 portion)
Calories 355 Calories from Fat 212
% Daily Value*
Fat 23.5g36%
Saturated Fat 12.8g64%
Cholesterol 67mg22%
Sodium 364mg15%
Potassium 839mg24%
Carbohydrates 25.4g8%
Fiber 4g16%
Sugar 5g6%
Protein 15.6g31%
Calcium 121mg12%
Iron 4mg22%
* Percent Daily Values are based on a 2000 calorie diet.

Nutritional information is approximate, and will depend on your exact ingredients. Please calculate your own nutritional values if you require accuracy for health reasons.

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Recipe Rating


  1. I made this tonight and it was divine. A huge hit, and my husband is already talking about the next time we have it. One question: we’ve never had brie before. Was I supposed to remove the rind?5 stars

  2. I made this last night for my veggie gf. It was very straightforward, and tasted great. I’m now very popular.

    thank you!

  3. I’m a big fan of anything with gratin in the title. Specially in potato is in front of it. One of your best so far!!