Mince the onion and place it in a microwave-safe container. Add olive oil and microwave at 600W for 1 minute. Let it cool.

In a bowl, mix the ground meat, cooled onion, and the meat mixture ingredients (breadcrumbs, milk, salt, pepper, nutmeg) until sticky. Divide into two portions.

Divide the pizza cheese into two portions and shape into balls. Place each cheese ball on a portion of the meat mixture and wrap the meat around it, shaping into an oval patty.

Heat salad oil in a frying pan over medium heat. Add the patties and cook until browned. Flip, cover with a lid, and cook on low heat for 7–8 minutes. Remove from the pan.

In the same pan, add ketchup and Worcestershire sauce. Heat over medium heat, stirring until it bubbles. Simmer for 1 minute, then add butter and mix to make the sauce.