Grate the onion and squeeze out the juice. You can save the pulp to make delicious recipes such as Turkish Grilled Lamb Kofta - Izgara Kofte or Turkish Sarma Lamb Beyti Kebab. Set the juice aside to use for doner kebab. Combine the ground lamb or beef, onion juice, yogurt, salt, paprika, and black pepper in a large bowl. Mix well for 8 to 10 minutes, until all are thoroughly combined and the mixture is firm.
Cover the bowl and let it marinate for a minimum of 2 hours, preferably overnight if you have time.
When the meat is marinated, place it on a large piece of tin foil. Shape it into a log or cylinder, about 2-3 inches in diameter, and wrap it tightly, making sure it is compact and holds its shape.
Preheat your oven to 356°F (180°C) and line a baking tray with aluminum foil.
Thread two skewers through the log; they will make it easier to hold the doner vertically and slice thinly.
Place the doner log on the baking tray and cook the doner meat in your preheated oven for 50 minutes.
Remove the doner from the oven and let it rest for 15 minutes.
Peel off the tin foil and shave the meat thinly using a very sharp knife.
Return the sliced meat to the baking tray and place it in the oven for another 5-6 minutes, until the doner meat slices are nicely browned.