To make the pastry, put the flour and salt into a large bowl and rub in the chilled butter until the mixture resembles fine breadcrumbs.
Using a knife, mix in the egg yolk and then gradually add enough of the chilled water until the mixture comes together to form a dough – adding the water a little at a time will prevent the dough from becoming too sticky.
Grease a 23cm diameter, 3cm deep tart tin, and line with the pastry. Chill in the refrigerator for 30 minutes.
Preheat the oven to 200°C (fan 180°C)/400°F/gas mark 6). Remove the pastry case from the refrigerator and prick the base with a fork. Line with greaseproof paper and cover with baking beans. Blind bake for 15 minutes, then remove the beans and paper and cook for further 10 minutes, or until golden.
Meanwhile to make the filling, heat half the olive oil in a heavy-based pan. Add the red onions, sprinkle with a little salt and cook gently over a very low heat, stirring occasionally, until the onions release their natural sugars and begin to turn golden. This will take about 10–12 minutes.
Preheat the oven to 200°C (fan 180°C)/400°F/gas mark 6. While the onions are cooking, brush the aubergine slices with the remaining olive oil and heat a griddle or frying pan. Place the aubergines on the hot griddle pan and cook until lightly browned on both sides. You may have to do this in batches.
Put the ricotta into a medium-sized bowl and mix until smooth. Add the eggs and cream, and season with salt and pepper.
Cover the base of the cooked pastry case with the softened onions and then overlap the slices of aubergine and halloumi on top.
Cover this layer with the halved cherry tomatoes. Pour over the ricotta and egg mixture and finally cover the top of the tart with the anchovies, capers and a generous sprinkling of oregano leaves.
Return to the oven for 20–25 minutes, or until set and golden. Drizzle with olive oil before serving.
Tart It Up!
Tart It Up, published by Mitchell Beazley