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Gluten-Free Brie & Onion Tart – the perfect alfresco dish!
This gluten-free Brie and onion tart is perfect for outdoor dining, especially in Vienna where we are lucky to have many beautiful blue skies with long sunny days in Summer at agreeable temperatures.
The chestnut pastry base is amazingly tasty and buttery. It has a deep nutty flavour, but once combined with other flours and the butter, it mellows and works very well in pastry tarts or pies.
Chestnut flour is sold in most health stores, but if you have a powerful food processor or better yet, a Thermomix ®, grind packaged ready-cooked chestnuts into a breadcrumb texture. See my notes in the recipe card below on how to make your own chestnut flour.


Gluten-Free Brie & Onion Tart
Equipment
- Round quiche tin (25 cm)
- Food processor (optional)
- Pastry weights or dried beans
Ingredients
GLUTEN-FREE CHESTNUT PASTRY
- 280 g store-bought or homemade gluten-free plain flour
- 60 g chestnut flour * see notes
- 150 g butter, chilled and cut into small pieces
- 70 g mild cheddar, grated
EGG WASH
- 1 egg yolk
- 1 tsp water
BRIE & ONION FILLING
- 5 white or yellow onions, sliced thinly
- 4 tbsp butter
- 2 tbsp red wine vinegar
- 3 tbsp light or dark brown sugar
- 1 tsp nutmeg, ground
- 300 g Brie cheese, cut into even segments
- 1 tsp fresh thyme leaves, chopped
GARNISHING
- 5 sprigs fresh thyme
Instructions
GLUTEN-FREE CHESTNUT PASTRY
Making the dough
- Rub the butter into the flours by hand or blitz in a food processor until the mixture appears like breadcrumbs.
- Add the cheese and knead the dough for a few minutes by hand or pulse several times in the food processor.
- Once the dough has come together, cover and chill for 30 mins.
Baking the chestnut pastry
- Preheat the oven to 180°C/350°F.
- Roll out the pastry on a sheet of baking paper into a rectangular shape to fit in a long tart tin or a round quiche tin.
- Transfer the pastry to the tin by flipping the pastry over it. The pastry may fall apart slightly at the edges, but moulding and pressing the dough with any scraps of spare pastry will fix this.
- Cover the pastry base with baking paper overhanging the sides followed by pastry weights/dried beans in order to blind bake. * See notes
- Bake on the middle shelf for 15 minutes.
- Remove the tart tin from the oven. Using both hands, lift the overhanging baking paper holding the weights/beans and set it aside.
- Prick the pastry base with a fork (this prevents the pastry from bubbling up and rising) and brush it with some of the egg wash to give a crispier finish.
- Return the tart tin back to the oven to bake for another 15 minutes.
BRIE & ONION FILLING
- Slice the onions thinly.
- In a medium frying pan, melt the butter gently. Add the onions and fry gently for 20 minutes, stirring occasionally.
- When the onions look brown and transparent, add the red wine vinegar and sugar. Cook for further 10 minutes. Stir often.
- Add the nutmeg and chopped thyme leaves. Stir well.
- Add the onion mixture to the cooked pastry base.
- Top the onion mixture evenly with the Brie segments.
Baking the Brie & Onion Tart
- Bake on the middle shelf for 10 minutes Bake longer if the Brie needs to melt more but don’t let the Brie completely disappear and melt into the tart.
- Allow to down cool slightly and garnish with some fresh thyme sprigs.
Notes
- Keeps for 3 days chilled
- Chestnut pastry base is suitable to freeze
- Complete Brie & Onion Tart is not suitable to freeze
GOOD TO KNOW
* Chestnut flour can be made from packaged ready-cooked chestnuts. Finely blend the chopped chestnuts until it appears like fine breadcrumbs.

This tart can be eaten cold with Dijon mustard and a freshly made side salad.