Onion Tart With Balsamic Tomatoes

40ml olive oil
4-6 onions, thinly sliced
4 garlic cloves, chopped
6 anchovies (optional)
8 Roma tomatoes cut lengthwise
1 tbsp balsamic vinegar
1 tbsp finely chopped thyme leaves
2 tbsp creme fraiche
285g plain flour
170g cold unsalted butter, cubed
7g pack of fast-action dried yeast
2 eggs, beaten

1. To make the pastry, rub the flour and butter together with your fingers until the mixture resembles breadcrumbs. Stir in the yeast and a pinch of salt, then make a well in the centre, pour in the eggs, and work the mix with your hands until it comes together in a dough. Put it in a floured bowl, cover with cling film and leave to rise in a warm place for 2 hours.
2. Place tomatoes on a lined baking tray. Brush with balsamic vinegar and bake in a slow oven, 150°C, for 20 minutes.
3. Meanwhile, make the filling. Heat the oil in a pan over a low heat, then add the onion, garlic, anchovies and thyme. Gently fry for 20 minutes, or until the onions are soft, then take it off the heat and stir through the crème fraîche. Set aside.
4. Increase the oven temperature to 200C. Press the dough into a 22cm x 30cm tray, pour in the onion filling and leave to rise for 15 minutes.  Top with tomatoes and bake in the oven for 20 minutes, then lower the temperature to 180C and cook for a further 10-15 minutes. If the tomatoes look like they are starting to burn, cover with foil. Serve warm.

Recipe adapted from one from Margot Henderson