Season the minced beef with salt and pepper and divide into 4 equal portions. Cut the tomatoes, mozzarella and onions into slices and set aside. Wash the spinach and set it aside.
Cut open the burger buns and lightly brown the cut side on a toaster. Bring the minced meat in the form of burger patties and fry on both sides in a pan with a little fat. Put the mozzarella on the patties and let it stand for a few more minutes. Fry the bacon until crispy.
Then cover the burger in the following order: burger bun underside, spinach leaves, tomato slices, onion slices, garlic-balsamic mayonnaise, meat baked with mozzarella, bacon slices, some garlic-balsamic mayonnaise, burger buns top. Fix everything with a wooden skewer and serve warm.