- 8 tbsp butter
- 3 tbsp milk
- 1¼ cup all purpose flour
- 1 tsp baking powder
- ¼ tsp salt
- 3 tbsp olive oil
- 3 onions, finely sliced
- 2 tbsp chopped thyme
- 1 tsp sugar
- Salt and freshly ground black pepper
- 1 cup heavy cream
- 3 large eggs, beaten
- ¼ cup freshly grated Parmesan
- 2 tbsp tapenade
- 9-inch (23cm) tart pan with a removable bottom
- To make the pastry, melt the butter in the milk in a small saucepan over low heat. Stir the flour, baking powder, and salt together. Add to the saucepan and stir until the dough forms a ball. Remove from the heat and cool. Press firmly and evenly into a 9in (23cm) tart pan. Chill for 30 minutes.
- Preheat the oven to 375°F (190°C). Heat the oil in a frying pan over high heat. Add the onion and cook, stirring often, for about 5 minutes. Add the thyme and sugar, and season with salt and pepper. Reduce the heat to low and cook gently, stirring occasionally, for about 30 minutes, or until onions are very soft and slightly caramelized. Meanwhile, whisk the cream, eggs, and Parmesan together.
- Place the tart pan on a baking sheet. Spread the tapenade over the pastry bottom. Spread the onions on top of the tapenade and carefully pour in the cream mixture. Bake for 30 minutes, or until the filling is set and browned. Let cool on a wire cake rack. Remove the sides of the pan, slice, and serve warm or cool to room temperature.