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.
I doubled the recipe below as I made a 30cm tart.
- 200gm flour
- 100gm butter
- 50gm parmesan cheese, finely grated
- 1 egg
- 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
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.
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.