Mushroom, Caramelised Onion and Gruyère Tart

I love love love puff pastry.

It’s so rich, and buttery and yummy the way it falls into little flakes. It’s completely impossible to eat without getting a little bit (or a lot) messy and it’s totally rewarding and even more satisfying when you’ve made it yourself.

There are loads of advocates of the shop-bought puff. Chefs who say that making your own isn’t necessary, that it’s too much bother. True, it takes a truly laborious degree of rolling, and turning, and waiting and incorporating a scarily big block of butter. But it’s totally worth it at the end.


I use puff pastry mostly in savoury rather than sweet recipes. So here it’s been turned into a really simple but very delicious tart.  I’m not very good at rolling out my pastry into a perfect rectangle, so always end up with a lot of offcuts. I ended up making a second smaller tart, into which I poured the remaining egg from the eggwash. That worked so well I’ve incorporated it into the recipe below.


You can also make cheese straws, palmiers, or even jam tarts from the pastry odds-and-ends. All so scrummy, but how could it not be, with homemade puff pastry? 🙂

Mushroom, Caramelised Onion, and Gruyère Tart

  • 400g puff pastry
  • 25g butter
  • 1 red onion, sliced finely
  • 1 dsp brown sugar.
  • 2 large handfuls mixed mushrooms
  • 20g dried porcini mushrooms
  • 1/2 tbsp garlic paste
  • salt and pepper
  • 50g Gruyère cheese, finely grated
  • 1 egg, lightly beaten
  • fresh parsley, chopped

Put the porcini mushrooms in a bowl of water to soak. Roll out the puff pastry. Lay out onto a baking tray, and cut into a neat rectangle. Score a border at least 1 cm from the edge. Prick all over the middle with a fork, and put into the fridge to chill.

Preheat the oven to 200˚C.

Melt the butter in a pan and add the onion. Cook until soft. Add the brown sugar, and mix in well until the onions are thoroughly coated. Add the oyster mushrooms, and cook until soft and glossy. Add the garlic paste, salt and pepper, taste and adjust further if needed.

Dry the porcini mushrooms, and cut into small pieces, then mix together with the rest of the mushrooms.

Sprinkle a little cheese over the centre of the puff pastry rectangle, then spread the mushroom mixture up to the edges. Pop into the oven and bake for around 15 minutes until risen and puffy, then gently pour into the tart the remaining egg, and sprinkle over with the remaining cheese. Bake a further 10-15 minutes until the pastry is golden-brown, and the egg is just set and lightly golden. Sprinkle over with a little fresh parsley and serve.


5 thoughts on “Mushroom, Caramelised Onion and Gruyère Tart

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s