Caramelised onion and greens pie
For the pastry
125g cold salted butter (or 125g unsalted butter, plus ½ teaspoon sea salt), plus extra for greasing
250g 00 flour
4 tablespoons ice cold water
For the filling
50g salted butter (or 50g unsalted butter, plus ¼ teaspoon sea salt)
1/4 teaspoon pure sea salt in a finer flake
4 onions, finely sliced
150ml double cream
2 heaped tablespoons full fat crème fraiche
1 heaped teaspoon Dijon mustard
50g parmesan, grated
100g curly kale, tough stalks removed
Leaves from a small bunch of parsley, roughly chopped
2 tablespoons capers in brine, drained
A handful of basil leaves
This recipe is one of three we are publishing to celebrate the launch of Castle Dairies beautiful new Welsh butter, made with none other than Halen Môn pure sea salt. Rich, creamy and absolutely delicious.
This highly portable pie is delicious on its own or as part of a spread. With a buttery, crumbly pastry encasing sweet onions and minerally green veg, it’s fantastic slightly warm or at room temperature. Try it with our gherkin relish.
Start by making the pastry. Cut the butter into cubes and pulse the butter and flour (and salt, if adding) together in a food processor until the mixture resembles bread crumbs. Pour in the water, a tablespoon at a time, pulsing between each addition. Remove the lid and pinch the dough together between your fingers. It should still be crumbly, but should hold together. If it doesn’t hold, add a tablespoon more water and pulse again until it does. Transfer the dough to a clean work surface and bring together with clean hands. Shape into a disc and wrap tightly in cling film. Transfer to the fridge to chill for 45 minutes.
Meanwhile, cook the onions. Melt the butter in a large (28cm) deep frying pan until it begins to sizzle, then add the onions and salt and stir to combine. Cook over a medium heat, stirring regularly, until the onions are translucent, about 10 minutes. Turn the heat down to low and continue to cook for another 25 – 30 minutes, until the onions are a deep amber, glossy and sweet. Remove from the heat.
Preheat the oven to 180°c. Lightly grease a 20x30cm loose bottomed tart tin with butter and line the base with baking parchment. Remove the chilled dough from the fridge and use the largest holes on a box grater to grate the dough into the centre of the tin, pressing into the base and sides of the tin as you go to form an even pie crust. The dough is very crumbly (making for a short and crisp cooked pastry base), so this is easier than rolling as it’s prone to break.
Cover the pastry with baking parchment and fill the parchment with baking beans. Bake in the oven for 15 minutes, before removing the beans and parchment and continuing to bake for 12 minutes to cook the base. Remove the pastry from the oven and leave the oven on.
Spread the cooled onions over the base of the pastry. Whisk the eggs, cream, crème fraiche and parmesan together in a mixing bowl, cover and set aside. Wash the kale, then wilt in a large saucepan with a lid until tender, using just the water that clings to the kale leaves. The kale is done when it’s bright green and tender. Refresh under cold water, squeeze to remove as much moisture as possible, then roughly chop. Stir the chopped kale into the egg and cream mixture with the parsley. Pour the green custard over the onions and scatter the capers over the top.
Bake the pie in the oven for 25-28 minutes until the filling is set. Allow to cool in the tin for 15 minutes, before removing and topping with basil leaves. The pie is best eaten on the day or day after it’s made, but will keep covered in the fridge and can be gently reheated up to four days after it’s baked.
Serve with fresh fruit and cheese as part of a picnic spread or outdoor lunch.
RECIPE + IMAGE: Anna Shepherd