Caramelised Onion and Cheese Quiche (with a gluten-free cheese and mustard pastry)

Serves 6-8

Whilst cheese and onion is a classic combination, caramelising the onions with a little balsamic vinegar adds a beautiful sweetness. Enhancing the pastry with cheese and wholegrain mustard gives an extra flavour kick and helps liven up the gluten-free crust.

Now, if you are looking for a quiche recipe and don’t need it to be gluten-free, then by all means make a regular shortcrust pastry by omitting the xanthan gum, replacing the gluten-free plain flour with regular flour, leaving out the eggs and just using a little water to bind it.

I used a vintage gruyere in the pastry and as half of the cheese topping. I used vintage cheddar in the filling and as the other half of the topping. You don’t need to use a mix, but I would recommend using a strong hard cheese to make sure the flavour comes through.

• Ingredients:

• For the pastry:
• 350g gluten-free plain flour
• 1/2 tsp xanthan gum
• 125g cold unsalted butter, cut into small cubes
• 25g gruyere, grated (or other hard cheese of your choice)
• 1 heaped tsp wholegrain mustard
• 2 eggs, beaten

• For the caramelised onions:
• 2 tbsp olive oil
• 4 small or 2 medium red onions
• Pinch salt
• 1 tbsp balsamic vinegar

• For the filling:
• 4 eggs
• 150ml milk
• 60g grated vintage cheddar
• Pinch of salt and white pepper

• For the topping:
• 50g grated cheese (I used a mix of gruyere and vintage cheddar)
• Pinch of thyme

Step 1: Make the pastry. Rub the butter and cheese in to the flour and xanthan gum until it resembles breadcrumbs.

Step 2: Add the mustard to the beaten egg and pour in to the breadcrumbed flour. Mix with your hands until combined and then roll or press out until about 4-5mm thick.

Step 3: Butter a loose-bottomed flan tin (20-25cm) and press the pastry into it; the gluten-free pastry is likely to tear, but patch it up to ensure there are no gaps.

Step 4: Leave to chill in the fridge for 30 minutes. Whilst this is chilling, caramelise your onions.

Step 5: Put the oil in a frying pan on a medium-low heat. Add the sliced onions and cook gently for 15 minutes, stirring occasionally.

Step 6: Add a pinch of salt and continue to cook for another five minutes on a gentle heat.

Step 7: Add the balsamic vinegar and stir for two minutes.

Step 8: Turn off the heat and allow to cool.

Step 9: Preheat the oven to 180c. Place baking parchment on top of the pastry along with baking beads or dry rice and blind bake in the oven for 20 minutes.

Step 10: Whisk the four eggs with 60g of grated cheese, the milk, a few of the thyme leaves, and the salt and pepper.

Step 11: Remove the pastry from the oven and carefully take out the beads and paper.

Step 12: Spread the cooled caramelised onions over the base and sprinkle over a few of the thyme leaves.

Step 13: Carefully pour over the egg mixture and return to the oven for 20 minutes.

Step 14: Sprinkle over the 50g of grated cheese(s) and the remaining few thyme leaves. Return to the oven for 15 minutes.

This can be served hot, warm or cold. If you make it in advance but would like to serve it hot, reheating it at 160c for 20 minutes should do the trick.