slow roasted tomato tart with caramelised onions and gruyere

tomatoes about to be slowly roasted

This recipe evolved over the day as I was cooking all the other things for my birthday. When I have a lot of tomatoes that need to be used up, I roast them either with a few herbs or with garlic and onions and then normally whizz into a delicious tomato sauce (for pasta, chicken, fish etc). Slow roasting them is another solution. I cut about 10 tomatoes in half, drizzled with olive oil and sprinkled generously with thyme and maldon salt and roasted at 150 degrees for about an hour and a half. The flavour of the tomato intensifies so dramatically it really is worth the time and effort on this one.

roasted and ready

I doubled the recipe below as I made a 30cm tart.

recipe:

pastry:
200gm flour
100gm butter
50gm parmesan cheese, finely grated
1 egg
filling:
1 red onion thinly sliced
1 Tbs balsamic vinegar
1 Tbs brown sugar
a knob of butter
50 gms of guyere cheese grated
5 tomatoes
olive oil
thyme

how to make:

Cook the tomatoes as per above
To make the pastry, whizz the flour and butter in a food processor until it resembles breadcrumbs. Stir in the parmesan, then the egg, and bring together to make a dough. Wrap in cling film and chill for 20 minutes
roll the pastry out to cover a 23cm low tart tin (I doubled the pastry to make a bigger tart and found that I had too much) and bake blind for 10 minutes. Remove from the oven and take out the baking paper and beans etc and bake for a further 5 minutes. Allow to cool a bit
melt a knob of butter in a frying pan and gently fry the onion until soft. Add the balsamic vinegar and sugar and cook for a few more minutes until the onions are nice and gooey (do either one or two onions)
spread the caramelised onion over the bottom of the tart, sprinkle over 80% of the cheese, then layer the slow roasted tomatoes on top, cut side up and sprinkle over the remaining 20% of the cheese.
bake for about 20 minutes @ 180 degrees

This was a complete success and not only does it look beautiful, the intense tomato-ie-ness, the sweet onions and the nutty gruyere marry so well together.

succulent and crunchy tart

The pastry is really easy to make an has a nice crisp texture (reminiscent of a cheese straw)– so I will definitely use this again. I had a bit extra as I doubled the recipe, so made another small tart and filled this with some odds and ends from my fridge, onion marmalade, courgette slices, feta, olives and gruyere.