Red onion, carrot and hazelnut tatin recipe

Root veggies and puff pastry combine to make this hearty tart

A savoury version of the French classic from pie aficionado Calum Franklin, this vegetarian upside-down tart comes with a caramelised filling and makes a tasty lunch or dinner.

You can either make the pastry by hand or use shop-bought puff pastry if you prefer.

Red onion, carrot and hazelnut tatin recipe

Ingredients:
(Serves 2-3)

3 red onions
4 large carrots, peeled and cut into 3cm chunks
2tbsp vegetable oil
½tsp fine table salt
30g whole blanched hazelnuts
15g butter
15g caster sugar
2tsp balsamic vinegar
10g tarragon, leaves picked and placed in iced water
150g rough puff pastry (see below, or use shop-bought puff pastry)

To make the pastry:
500g plain flour
1tsp fine table salt
500g butter, chilled and diced
250ml ice-cold water

1. If making the pastry by hand, sift the flour into a large bowl and add the salt and butter. Using your fingers, gently mix to a rough dough. If making the pastry using a mixer, sift the flour into the bowl and add the salt and butter. Using a paddle attachment, work at a medium speed for two to three minutes until the butter has formed small nuggets and the mixture becomes grainy.

Add the ice-cold water all at once to the flour and butter and continue at a medium speed just to bring the dough together. The dough should not be well mixed; you want the dough to be straggly and rough, with the fats still visible, so don’t work it for too long.

2. Tip the mixture out onto a lightly floured surface and carefully knead the dough until all the flour is incorporated. Flatten the dough slightly, wrap it tightly in cling-film and chill in the refrigerator for 30 minutes.

3. On a lightly floured surface, roll out the dough to a rectangle measuring 50cm by 30cm, using the sides of your hands to make sure the edges are neat and square.  Dust any excess flour from the surface of the dough. With the shortest side closest to you, visually divide the dough horizontally into thirds and very lightly dampen the centre third with a little water, then fold the bottom one third of the dough over the centre third. Repeat by folding the remaining top third over the double layer of dough.

4. Turn the dough 90 degrees clockwise and repeat the rolling and folding process. This makes up the first two turns. Tightly wrap the dough in cling-film. Lightly press your finger into the bottom right-hand corner of the dough to make an indentation which signifies how the dough was positioned on the board before you put it into the refrigerator. Chill the dough in the refrigerator for 30 minutes.

5. Unwrap the dough and place it on your work surface with the indent in the same position as before at the bottom right-hand corner. Next, turn the dough 90 degrees clockwise and repeat the rolling and folding processes two more times for the final two turns. Chill in the refrigerator for at least 40 minutes before it is ready to use.

Red onion, carrot and hazelnut tatin

Method:

1. Preheat the oven to 210°C fan/230°/gas mark 8.

2. Peel the onions and cut them in half through the roots so they stay intact, then cut each half through the root again into four wedges.

3. Place the carrot chunks and onion wedges in a large roasting tray, toss with the vegetable oil and salt then spread over the base of the tray. Place the tray in the preheated oven and roast the vegetables for 30 minutes or until they start to colour. Add the hazelnuts to the tray and roast for a further five minutes.

4. In a heavy ovenproof frying pan, warm the butter, sugar and balsamic vinegar until the sugar has dissolved. Bring the mixture to the boil and continue cooking until it has thickened enough to coat the back of a spoon. Add the roasted vegetables and nuts to the pan, toss well in the mixture and set aside to cool for 10 minutes.

5. On a lightly floured surface, roll out the pastry dough into a 1cm thick circle large enough to cover the frying pan. Bunch the vegetables and nuts together so there is a 2cm gap around the edge of the pan and then cover with the pastry, tucking it slightly under around the edge. Prick the pastry all over with a fork.

6. Place the frying pan in the hot oven and bake the tarte tatin for 20 minutes or until the pastry is puffed up and golden. Taking care to protect your hands with a heatproof cloth as the handle will be very hot, remove the pan from the oven. Place a large flat plate over the top of the pan and then quickly flip it over. Dress the top of the tarte tatin with the iced tarragon leaves and serve while warm.

The Pie Room by Calum Franklin, photography by John Carey, is published by Bloomsbury Absolute available now from Amazon.