WALNUT, MUSTARD AND CARAMELISED ONION TART

Indulgent, yes (there’s a fair amount of butter and cream here) – but completely delicious and always crowd-pleasing. This is not at all difficult, especially if you use shop-bought pastry for the base (the tart will still be wonderful but the shell won’t be quite as flaky and golden as if you’d made the pastry). I like to double this recipe to make two tarts, one for now and one for the freezer.

Serves six

INGREDIENTS

For the rough puff pastry 250g chilled butter, cubed 250g plain flour, plus extra for dusting 60ml chilled water

For the filling

2 tbsp olive oil 3 brown onions, sliced 3 eggs

250ml single cream 2 tsp wholegrain mustard 50g grated Comte or gruyère cheese

115g walnuts, lightly toasted and roughly chopped

METHOD

To make the pastry, combine the butter and flour on the work surface, using the heel of your hand to work them together. Add chilled water as necessary to form a rough dough – it’s okay to see some marbled streaks of butter. Cover and chill for 30 minutes. Roll out the pastry on a lightly floured surface into a large rectangle. Dust off any loose flour. Fold the top half of the pastry down, then fold the bottom half up so you have a long slim rectangle. Turn the pastry 90 degrees and roll it into another large rectangle, rolling in one direction if possible (this helps keep your pastry nice and flaky). Fold and roll the pastry into another slim rectangle, then cover and chill for 20 minutes.

Roll out the pastry on a lightly floured surface until 3mm thick. Gently drape the pastry over a 36 x 11cm loose-based rectangular tart tin and trim the edges. Return to the fridge for 30 minutes. Preheat the oven to 180C/160C fan/Gas 4. To make the filling, heat the olive oil in a heavybased saucepan over medium heat. Cook the onion, stirring often, for about 20 minutes or until golden and completely caramelised. Meanwhile, line the pastry with baking paper and fill the base with pastry weights, uncooked rice or dried beans (this stops the base rising during baking). Bake for 20 minutes. Remove the weights and paper and bake for another 10 minutes or until the pastry is pale and dry. Combine the eggs, cream, mustard, cheese and a good pinch of sea salt in a bowl and whisk well. Scatter the caramelised onion over the pastry base, sprinkle with the walnuts, then gently pour in the egg mixture so it comes three-quarters of the way up the sides of the shell. Bake the tart for about 30 minutes or until the pastry is golden and the filling is just set.