Mince the onion and microwave it for 1 minute at 600W. Let it cool.

Mix breadcrumbs with milk in a bowl. Add ground meat, onion, and seasonings. Mix until sticky.

Spread half of the meat mixture in a 20cm frying pan. Add cheese in the center and cover with the remaining meat mixture, shaping it into a round patty.

Heat oil in the pan over medium heat. Cover and cook for 3 minutes on medium heat, then 5 minutes on low heat.

Remove excess oil with a paper towel. Flip the patty onto a plate, then return it to the pan. Cover and cook on low heat for 7–8 minutes until fully cooked.

Mix eggs with milk and salt in a bowl to prepare the egg mixture.

Clean the pan and heat butter over medium heat. Pour the egg mixture and stir gently. Place the hamburger patty on top and flip using a plate.