Preheat your oven to 180°C (350°F). Grease a 23cm round pie dish or a 20cm square baking dish with butter or oil. Set it aside while you prepare the filling.

Sweat the onion in olive oil over medium heat in a large frying pan. Cook for 4–5 minutes until the onion turns translucent and soft — you'll notice a sweet, mellow aroma rising from the pan. Add the minced garlic and stir for another 30 seconds until fragrant.

Wilt the spinach by adding it to the pan in handfuls. As it touches the hot oil, you'll hear a gentle sizzle and see the leaves collapse into a dark, tender mass. This takes about 2–3 minutes. Once all the spinach is wilted, remove the pan from the heat and let it cool slightly.

Whisk the eggs and cream together in a large mixing bowl until the mixture is pale yellow and completely smooth, with no streaks of egg white visible. The cream should be fully incorporated, giving the mixture a silky, uniform texture.

Combine the filling by stirring the cooled spinach mixture, crumbled feta, grated cheddar, salt, pepper, and nutmeg into the egg mixture. Stir gently but thoroughly — you want the cheese and spinach evenly distributed, not clumped in one corner.

Pour the mixture into the prepared dish. Give the dish a gentle shake to level the surface. You should see the liquid settle evenly, with flecks of green and white scattered throughout.

Bake for 35–40 minutes until the quiche is set. The top should be golden brown and slightly puffed, and the centre should feel firm to the touch — no jiggle when you gently shake the dish. A knife inserted into the centre should come out clean. The kitchen will smell richly of toasted cheese and eggs.

Cool for 10 minutes before slicing. This resting time allows the quiche to firm up, making cleaner slices. If you cut too soon, the texture will be loose and messy.