A Classic Caramelised Onion & Gruyère Quiche (From Scratch)

This is my go-to caramelised onion & Gruyère quiche. Rich, savoury, and made completely from scratch. With buttery shortcrust pastry, slow-cooked caramelised onions, a silky custard, and plenty of Gruyère, this is a simple classic that never fails.

Perfect served hot or cold for lunch, dinner, or entertaining.

Watch The Recipe Video Below

A Classic Caramelised Onion & Gruyère Quiche (From Scratch)

Ingredients

Shortcrust Pastry

200g x Plain (all-purpose) Flour

1 tsp x Salt

100g x Cold Butter (cubed)

1 x Egg Yolk

1 Tbsp cold water (add more if needed)

Egg wash (for sealing pastry)

Custard Filling

240ml x Milk

240ml x Cream

A few sprigs of fresh thyme

3 x Eggs

Salt, to taste

White pepper, to taste

Caramelised Onions

6 x Small Onions (or 3 large), thinly sliced

30g x Butter

Small Pinch of Salt

5-6 x Sprigs Fresh Thyme (leaves picked)

To Assemble

100g x Gruyère Cheese (grated)

Extra Gruyère (for topping)

Thyme Leaves

Method

Make the Pastry

Place the flour and salt into a food processor (or mixing bowl if doing by hand).

Add the cold butter and pulse (or rub in by hand) until the mixture resembles breadcrumbs.

Add the egg yolk and pulse again until incorporated.

Add around 1 tablespoon of cold water and pulse until the dough just starts to come together. Add a little more water if needed.

Once the dough clumps together, remove it, press into a ball, then flatten into a disc.

Wrap and refrigerate for at least 30 minutes.

Prepare the Custard Base

Place the milk and cream into a heavy-bottomed saucepan.

Add the thyme sprigs.

Heat gently until just below boiling. When you see steam, remove from the heat.

Stir occasionally to prevent burning or skin forming.

Set aside to cool and continue infusing.

Roll & Blind Bake the Pastry Case

Preheat the oven to 170°C fan.

Lightly flour your work surface and roll the chilled pastry to about 2mm thick.

Roll the pastry over a rolling pin and lay it into a 25cm tart tin, gently pressing it into the corners.

Don’t worry if it cracks, simply press it back together.

Dock the base by pricking it all over with a fork.

Leave the pastry overhang in place.

Line the pastry with scrunched baking paper and fill with baking beans or rice.

Blind bake for 20 minutes.

Remove the rice and paper, then return the pastry to the oven for 5 minutes.

Brush the base lightly with egg wash and bake for a further 5 minutes to seal.

Remove from the oven and trim the excess pastry using a small knife or potato peeler.

Brush away any crumbs and set aside.

Caramelise the Onions

Melt the butter in a pan over medium-low heat.

Add the sliced onions and a small pinch of salt.

Add the thyme leaves and stir.

Cook gently, stirring occasionally, until the onions are soft, golden, and caramelised.

Be patient, do not rush or allow them to burn.

Once done, remove from the heat.

Finish the Custard

Crack the eggs into a mixing bowl.

Strain the cooled milk and cream mixture through a sieve into the eggs.

Season with salt and white pepper.

Whisk until fully combined.

Assemble the Quiche

Spread the caramelised onions evenly over the base of the pastry case.

Sprinkle over the grated Gruyère cheese.

Pour the custard mixture carefully over the filling.

Top with a little extra Gruyère and a sprinkle of fresh thyme.

Bake

Bake at 170°C fan until the quiche is just set with a slight wobble in the centre. This should take around 35 to 40 minutes.

Remove from the oven and allow to cool slightly on a rack.

Serve hot or cold.