Stilton, Spinach & New Potato Quiche with Paprika and Walnut Pastry

STEP 1: MAKE THE PASTRY Toast the walnut halves in a dry large skillet over medium heat for 3–4 minutes, shaking the pan, until fragrant, then let them cool completely. Pulse the cooled walnuts in a food processor until finely ground, stopping before they turn oily. Add the flour, sweet paprika and 1/2 teaspoon salt and pulse to combine. Add the cold butter and pulse until the mixture looks like fine crumbs. Add the egg yolk and 2 tablespoons of ice water and pulse just until the dough starts to clump, adding a little more water only if needed. Tip out, press into a flat disc and wrap. Do not knead: overworked pastry turns tough. Chill for 30 minutes.

STEP 2: LINE THE TIN Roll the pastry between two sheets of parchment paper to about 1/8 inch (3 mm) thick and a circle about 12 inches (30 cm) across. Walnut pastry is short and can tear, so patch any gaps with offcuts. Ease it into the tart tin, press it into the flutes and leave a little overhang. Prick the base lightly with a fork and chill for another 30 minutes. Place a baking sheet in the oven and preheat to 400°F (200°C).

STEP 3: PREPARE THE FILLING While the lined tin chills, bring a medium saucepan of water to a boil with 1 tablespoon salt. Simmer the potatoes for 12–15 minutes until just tender. Drain, cool slightly and slice into 1/4-inch (5 mm) rounds. Melt the butter in the large skillet over medium heat, add the spinach and cook, stirring, for 2–3 minutes until just wilted. Tip into a sieve, let cool, then squeeze out as much liquid as you can and chop roughly. Excess water from the spinach is the main threat to a set custard and a crisp base.

STEP 4: BLIND BAKE THE CASE Line the chilled case with crumpled parchment paper and fill with pie weights. Bake on the hot baking sheet for 15 minutes. Remove the parchment and weights and bake for 5–8 minutes more until the base looks dry and lightly golden. Brush the inside of the hot case with the beaten egg white and return it to the oven for 1 minute to set the seal. Trim the overhang with a sharp knife. Reduce the oven to 350°F (180°C), leaving the baking sheet in the oven.

STEP 5: MAKE THE CUSTARD Whisk the eggs, heavy cream, milk, black pepper, nutmeg and 1/4 teaspoon salt together until smooth. Strain through the rinsed sieve into a large pitcher to remove any stringy egg white.

STEP 6: ASSEMBLE AND BAKE Arrange the potato slices over the base of the case, then scatter the spinach and Stilton evenly between them. Set the tin on the hot baking sheet in the oven and pour in the custard from the pitcher, filling to just below the rim. Bake for 30–35 minutes until the custard is set at the edges with a slight wobble in the center and the top is patchily golden. Take it out at the wobble: an overbaked custard turns grainy and weeps.

STEP 7: REST AND SERVE Let the quiche rest in the tin for at least 20 minutes so the custard finishes setting, then remove it from the tin. Serve warm or at room temperature.