James Martin Onion Tarte Tatin

This James Martin Onion Tarte Tatin is a beautifully caramelised savoury tart with sweet, soft onions and crisp golden pastry. The rich buttery flavour pairs perfectly with the deep sweetness of slow-cooked onions, creating a dish that feels both rustic and elegant. It is surprisingly simple to make, even for beginners, with a few careful steps. From start to finish, it takes around 1 hour and 15 minutes.

Ingredients

For the onion filling

6 large onions, peeled and thickly sliced
50g unsalted butter
2 tbsp olive oil
1 tbsp balsamic vinegar
1 tbsp brown sugar
Salt and black pepper, to taste
2–3 sprigs fresh thyme

For the pastry topping

1 sheet ready-rolled puff pastry
1 egg, beaten (for glazing)

How to Make James Martin Onion Tarte Tatin

Prepare the oven: Preheat the oven to 200°C or 180°C fan. Place a shelf in the middle of the oven so the tart cooks evenly and the pastry rises beautifully.
Cook the onions: Heat the butter and olive oil in a large ovenproof frying pan over medium heat. Add the sliced onions and cook gently for 20–25 minutes, stirring occasionally, until soft and lightly golden.
Caramelise the filling: Stir in the balsamic vinegar, brown sugar, thyme, salt and pepper. Cook for another 5–10 minutes until the onions are deeply caramelised and glossy.
Prepare the pastry: Remove the pan from the heat and allow the onions to settle into an even layer. Lay the puff pastry over the top, tucking the edges down inside the pan.
Glaze and bake: Brush the pastry with beaten egg. Transfer the pan to the oven and bake for 25–30 minutes until the pastry is puffed and golden brown.
Cool slightly: Remove from the oven and leave to rest for 5 minutes to allow the caramel to settle.
Turn out and serve: Carefully invert the tart onto a serving plate so the onions are on top. Serve warm.

Tips

How do I stop the onions from burning?

Cook them gently over medium to low heat and stir regularly. If they start to catch, reduce the heat and add a small splash of water.

Can I make this ahead of time?

Yes, prepare and bake the tart, then reheat gently in the oven before serving for the best texture.

Why is my pastry soggy?

Make sure the onions are well caramelised and not watery before adding the pastry. Excess moisture can affect the crispness.

Do I need an ovenproof pan?

Yes, using an ovenproof frying pan makes the process easier, but you can transfer the onions to a baking dish if needed.

Serving Suggestions

Serve with a crisp green salad
Add a dollop of crème fraîche on the side
Pair with roasted vegetables for a hearty meal
Enjoy as a starter or light lunch

Storage

Room Temperature

Keep covered for up to 6 hours. Best served fresh for optimal texture.

Refrigerator

Store in an airtight container for up to 3 days. Reheat in the oven to restore crispness.

Freezing

Freeze for up to 2 months. Wrap well and thaw overnight in the fridge before reheating.

Nutrition

Calories: 380 kcal
Carbohydrates: 35g
Protein: 5g
Fat: 24g
Saturated Fat: 10g
Sodium: 320mg

These values are approximate and may vary depending on ingredients used.

FAQs

Can I use red onions instead?

Yes, red onions work very well and give a slightly sweeter flavour and deeper colour.

Can I make this without puff pastry?

You can use shortcrust pastry, but the texture will be less light and flaky.

How do I turn the tart out neatly?

Let it rest for a few minutes after baking, then place a plate over the pan and carefully flip it in one quick motion.

Can I add cheese to this recipe?

Yes, adding a little goat’s cheese or grated cheddar before the pastry goes on gives extra richness.