Preheat your oven to 180°C (160°C fan) and generously butter a 20cm round pie dish or a 20cm square baking dish. The butter helps release the quiche cleanly and adds a lovely golden edge.

Heat the olive oil in a large frying pan over medium heat. Add the diced onion and cook for 4–5 minutes, stirring occasionally, until the pieces turn translucent and glossy and release a sweet, savoury aroma.

Stir in the minced garlic and cook for 30 seconds until fragrant — you’ll smell it immediately, so don’t walk away. Add the spinach in handfuls, letting each batch wilt down before adding more. The leaves will turn a deep, vivid green and reduce dramatically in volume. This takes about 2–3 minutes total.

Transfer the cooked spinach mixture to a clean tea towel or a fine-mesh sieve. Press gently with the back of a spoon to extract as much liquid as possible. This step is crucial — excess moisture will make your quiche watery and prevent it from setting properly.

In a large mixing bowl, whisk the eggs until they are frothy and pale yellow, about 30 seconds of vigorous whisking. Add the double cream, milk, salt, pepper, and nutmeg, and whisk again until the mixture is completely smooth and uniform in colour.

Fold the squeezed spinach mixture, crumbled feta, and grated Parmesan into the egg base. Stir gently until everything is evenly distributed — you should see flecks of green and white throughout the pale yellow custard.

Pour the mixture into the prepared dish and spread it evenly with a spatula. Bake for 28–32 minutes, until the top is golden brown and the centre feels just set when you gently shake the dish — it should wobble slightly but not slosh. A knife inserted into the centre should come out clean.

Let the quiche rest in the dish for at least 10 minutes before slicing. During this time, the residual heat finishes cooking the centre and the structure firms up, making slices clean and neat rather than messy.