1. Roll out the pie dough on a lightly floured work surface, and use to line the tart pan. Chill for 30 minutes.

2. Heat the oil in a large saucepan over low heat. Add the onions and cover. Cook, stirring occasionally, about 20 minutes, until the onions are meltingly tender. Uncover and cook for 4–5 minutes more, or until golden. Let cool.

3. Meanwhile, preheat the oven to 400°F (200°C). Line the tart crust with parchment paper and fill with pie weights. Bake about 10 minutes, until set. Remove the paper and weights and bake until beginning to brown, about 10 minutes more.

4. Reduce the oven to 350°F (180°C). Spread the onions in the shell. Whisk together the cheese, eggs, half and half, and caraway seeds. Season with salt and pepper and pour over the onions. Arrange the anchovies on top. Bake for 25 minutes, or until the filling is set. Cool slightly then remove the sides of the pan. Serve warm.