To make the shortcrust pastry, place flour, butter and salt in large mixing bowl. Using your fingertips, gently rub ingredients together until they resemble rough breadcrumbs. Do not over mix or the butter will begin to melt from the heat of your fingers. Add water and mix until a dough is formed. Cover with cling fi lm and refrigerate for 30 minutes or overnight. Gently re-work pastry before using, taking care to ensure it remains cold and firm.

Preheat oven to 230°C / 450°F.

Add 1 teaspoon of oil to a large sauté pan over medium heat. Add onion, salt and pepper, tossing to coat evenly. Cook 20 minutes, stirring often, until onions have softened and turned a lovely shade of golden caramel. Remove onions to a bowl and set aside.

Add remaining teaspoon of oil and add mushrooms, caraway, a little more salt and pepper. Toss to coat. Cook, stirring occasionally, until mushrooms have turned brown and released most of their liquid. Remove pan from heat and pour mushrooms onto a paper-towel lined plate in order to remove as much moisture as possible from them.

On a lightly floured surface, roll out shortcrust and transfer to a parchment-lined large rimmed baking sheet. Leaving a 2 to 3-inch border around the centre, spread out half of the onions on the dough. Layer with mushrooms and caraway mix, evenly distributing, and finish with remaining onions. Sprinkle with a little more pepper. Top with the shredded cheese. Fold in sides of the dough circle roughly, pressing slightly to adhere pieces to one another. Brush edges of dough with milk.

Bake for 25 to 30 minutes, until crust is golden and cheese is bubbling. Garnish with remaining fresh caraway. Remove and allow to rest for 5 minutes before cutting into slices. Imen McDonnell is a food writer, photographer and filmmaker.