THE GRUMPY COOK CLUB
ONION, POTATO & GRUYERE TART
After the success of this tart at a recent al fresco do we had with friends and neighbours, I am compelled to share its vegetarian delights with you.
There are tarts, and there are tarts, but this one is on another level, based on a recipe from leading Scottish chef Martin Wishart.
Being rich, creamy and earthy all at the same time, it has something for everyone, whether it’s a portion at a party, or a slice with a crisp green salad for supper.
The combination of sautéed potatoes and slow-cooked onions, bound together with eggs, cream and cheese is an absolute delight, and even makes a meat-eater like me forget carnivorous pleasures (for one meal anyway).
Although it has similarities with a quiche in its ingredients, that is where the similarities end.
This is a tart for grown-ups.
(for a 30cm tart)
300g plain flour
150g cold butter, cubed
Few tbs of cold water
Put flour, butter and salt in a food processor and pulse a few times until you have a mix like breadcrumbs. This should only take seconds.
Then add cold water a little at a time while still pulsing, until the pastry just starts to clog together.
Tip out onto a cool work surface and form into a smooth ball, without kneading too much. Flatten a little, cover with clingfilm and put in the fridge for an hour to rest.
After the pastry has rested, take out of the fridge and allow the chill to come off the pastry.
Roll out to about the depth of a pound coin, and place into a 30cm tart tin. Press into the sides, trim off the excess, prick the base with a fork, cover with cling film and rest again in the fridge (even overnight).
Pre-heat your oven to 180℃/160℃ fan and put in a large baking tray.
To blind bake the pastry case, cover the tin with crumpled baking paper and fill with baking beans or rice to weigh everything down, making sure you get down into the edges.
Place onto the hot baking tray in the oven for about 15 minutes, then remove the baking paper and beans/rice.
Brush the base of the tart with some beaten egg, to create a seal, which will keep the base crisp, even when the wet filling is added later.
Put back in the oven for another 10 minutes or so until the pastry is a nice golden colour.
Keep an eye on the pastry at this stage, since all ovens differ, and my timings are only a guide.
Roll out, line the tin, prick base and chill...
...line with baking parchment and beans and blind bake for 15 minutes...
...seal with beaten egg and bake for another 10 minutes until golden.
For the filling
15-20 new baby potatoes
4 large onions, peeled and thinly sliced
400ml double cream
3 tbs grated parmesan
100g Gruyere cheese
Salt & pepper
Melt the butter in a large frying pan, and over a medium heat, cook the onions with a pinch of salt until meltingly soft, golden and sweet.
At the start, you will think there are far too many onions, but have faith, as they will cook down into just the right amount for the base of the tart.
The slower you cook the onions, the sweeter and better they will be, as this gives them plenty of time to release their natural sugars and caramelise into a golden brown tangle. (I cooked mine for about 45 minutes).
If you feel the onions aren’t as sweet as you would like, sprinkle with a little sugar to help the caramelisation, but keep tasting as you go.
This is the most important part of the tart so give it your best shot.
When the onions are done to perfection, leave to one side to cool.
Finely slice 4 large onions...
...then slowly sauté in butter...
...until golden and caramelised.
Boil the potatoes until just cooked through, drain, and cool.
Half them lengthways, and fry, cut side down, in a little olive oil until golden brown. Cool.
Half the cooked potatoes lengthways...
...saute in a little oil...
...until golden brown.
Combine the onions and potatoes (you might need to warm the onions a little to help them mix with the potatoes) and layer over the base of the cooked pastry case.
Try and get some of the potatoes to stand upright so they stick out of the surface of the tart filling, for no other reason than it looks great!
Beat the eggs with the cream and a pinch of salt, then stir through the parmesan.
Pour the egg and cream mixture over the onions and potatoes, to near the top of the tart, before putting it on the hot baking tray in the oven. With the little mixture remaining, top up the tart to as near the top as you can get it (don’t worry if there is a little egg and cream mixture left over*), and sprinkle over the grated Gruyere cheese.
Combine the onions and potatoes and layer over the base...
...pour over the egg and cream mix and sprinkle over cheese...
...bake until just set in the middle.
Carefully slide into the oven, and bake for about 20 minutes until it looks just set and golden brown on top.
If it still looks too ‘wobbly’ in the centre, just give it a few more minutes but keep checking. The filling should be set, but silky.
I think my tart took about 25 minutes in my oven.
When done, remove from the oven onto a cooling rack and leave to cool in the tin.
If you do have any egg, cream and parmesan left over, just pop it in a small ovenproof dish, bake until set and eat - it’s delicious!