Name: Cheese Flan with Caramelized Onion and Cheddar Recipe
Prep time: 20 min
Cook time: 40 min
Total time: 1 h
Cuisine: British
Ingredients: 15g salted butter, plus extra for greasing; 1 onion, finely chopped; 5 eggs, beaten; 150ml whole milk; 150g extra-mature cheddar, grated; 320g ready-rolled sheet of shortcrust pastry

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Introduction

This cheese flan is a rich and comforting dish featuring caramelized onions and sharp cheddar wrapped in a buttery shortcrust pastry. It’s perfect for a simple lunch or a cozy dinner with a fresh salad. The golden, puffed-up filling makes it as beautiful as it is delicious.

A rectangular baked dish with a thick, golden brown crust lining the edges holds a cheesy casserole that features a rich, bubbly top layer of melted cheese with browned spots and hints of black pepper scattered throughout. The casserole fills the entire dish, showing a slightly textured surface with melted cheese in a mix of creamy white and golden tones. Next to the dish is a scalloped white bowl filled with fresh green leafy salad and bright red cherry tomato halves. The setting is on a white marbled surface covered partly with a yellow checkered cloth, and a small, round container with a white lid and green floral design is nearby. A light blue glass cup is also visible in the scene. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

15g salted butter, plus extra for the dish
1 onion, finely chopped
5 eggs, beaten
150ml whole milk
320g ready-rolled sheet of shortcrust pastry
150g extra-mature cheddar, grated

Instructions

Step 1: Heat the oven to 200°C (180°C fan) or gas mark 6 with a baking tray inside. Melt the butter in a small pan over medium heat. When the butter foams, add the chopped onion and a large pinch of salt. Fry gently for 10-15 minutes until the onion softens and begins to caramelize. Remove from heat and let it cool slightly.
Step 2: In a bowl, whisk together the beaten eggs and whole milk, and season generously with salt and pepper.
Step 3: Butter an 18 x 25cm baking dish that is at least 6cm deep, then line it with baking parchment. Roll out the shortcrust pastry into the dish, pressing it fully into the corners and up the sides.
Step 4: Scatter the caramelized onion evenly over the pastry base, then sprinkle the grated cheddar on top. Carefully pour the egg and milk mixture over the filling.
Step 5: Place the baking dish on the hot baking tray in the oven and bake for 35-40 minutes. The flan should be golden on top and puffed up. Remove from the oven and allow to cool slightly before serving.

Tips & Variations

For extra flavor, add a pinch of freshly ground nutmeg or some chopped herbs like thyme or chives to the egg mixture.
Try swapping the cheddar for another strong cheese such as Gruyère or Comté for a different taste.
To prevent the pastry from shrinking, chill it in the fridge for 15 minutes before baking and avoid stretching it too much when lining the dish.

Storage

Store any leftover cheese flan covered in the refrigerator for up to 2 days. Reheat gently in a low oven (around 160°C) until warmed through to preserve the texture. Avoid microwaving as it may make the pastry soggy.

How to Serve

A rectangular baked dish with three visible layers: the bottom layer is a thick, golden-brown crust with slightly raised edges, the middle layer is a rich, dark red tomato sauce spread evenly, and the top layer is melted, bubbly cheese with golden brown spots and some black pepper sprinkled on it, all inside a white baking dish placed on a white marbled surface. Next to the dish, a brown scalloped salad bowl holds a fresh green salad with leafy greens and halved cherry tomatoes, sitting on a yellow checkered tablecloth. A blue-green glass and a small white salt shaker with green floral design are beside the salad. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make this cheese flan ahead of time?

Yes, you can prepare the flan up to the point of baking, cover it tightly, and refrigerate it overnight. Bake it the next day adding a few extra minutes to ensure it’s cooked through.

Can I use a different type of pastry?

Shortcrust pastry works best for this recipe because it’s sturdy enough to hold the filling. However, puff pastry can be used for a lighter, flakier base—just keep an eye on baking time as it may cook faster.