Prepare the meat mixture: In a large mixing bowl, combine the minced lamb, grated onion (well-squeezed), minced garlic, dried oregano, ground cumin, smoked paprika, cinnamon, salt, pepper, tomato purée, olive oil, breadcrumbs, and beaten egg. Use your hands to mix thoroughly—you should feel the mixture become slightly sticky and cohesive, with a fragrant, earthy aroma of spices. Cover the bowl with cling film and refrigerate for at least 1 hour. This resting time allows the flavours to meld and the breadcrumbs to absorb moisture, resulting in a firmer texture when cooked.

Shape the loaf: Turn the chilled meat mixture out onto a clean work surface. With slightly wet hands (to prevent sticking), shape it into a tight, compact loaf about 10cm wide and 5cm tall. It should feel firm and hold its shape without cracking. The surface should look smooth and evenly blended, with no visible lumps of onion or spice.

Brown the loaf: Heat a large frying pan over medium-high heat and add a generous drizzle of olive oil. Once the oil shimmers and ripples (you can test it by flicking a tiny piece of meat in—it should sizzle immediately), carefully place the meat loaf into the pan. Sear for 4-5 minutes without moving it, until the underside is a deep, mahogany brown and smells richly caramelised. The edges should look crisp and slightly frilly.

Cook through slowly: Reduce the heat to medium-low. Using two spatulas, carefully rotate the loaf a quarter-turn to sear a new side. Repeat this rotation every 4-5 minutes, cooking for a total of 20-25 minutes. You'll hear a gentle, steady sizzle rather than a frantic spatter. The loaf should feel firm to the touch when pressed, and a meat thermometer inserted into the centre should read 71°C for lamb (or 74°C for beef). The exterior will be a deep golden-brown with crunchy, textured patches.

Rest and slice: Transfer the cooked loaf to a baking sheet lined with kitchen paper and let it rest for 5-7 minutes. This resting period is crucial—it allows the juices to redistribute so your slices stay moist. When you slice the loaf with a sharp knife, you should see a uniform, tender interior with no raw spots. The crispy outer crust should shatter slightly under the knife, revealing the succulent meat within.

Finish with a flash fry (optional but glorious): For maximum crispiness, heat a clean pan with a tablespoon of oil over high heat. Add the sliced gyros meat in a single layer and fry for 60-90 seconds, tossing once. The slices will turn a shade darker and develop an audible crunch when you stir them. The kitchen will fill with an irresistible, smoky, oregano-laced fragrance.

Assemble and serve: Warm your pitta breads in a dry pan or oven until they puff slightly and smell toasted. Lay each pitta on a plate, pile on the crispy gyros slices, and garnish generously with fresh parsley. Serve immediately while the meat is still hot and the edges are at their crispiest.