1
Heat half a tablespoon of olive oil in a pan, sauté the string beans and red bell pepper until lightly browned, add a splash of water and cover to steam, stirring once midway. Remove when tender, season with salt and pepper, and set aside.
2
Wipe the pan clean, melt butter, and sauté chopped onion until the moisture evaporates and it turns translucent or slightly browned. Divide in half — chill one portion for the patties and keep the other in the pan for the sauce.
3
Mix milk into the soft panko until evenly moistened.
4
Combine ground beef and pork with salt, mixing until sticky. Push the meat to one side, add the chilled onion, moistened panko, egg, and black pepper into the empty space, mix those together first, then fold everything into the meat and mix thoroughly.
5
Divide the meat mixture into two portions, toss each firmly to remove air pockets, then with oiled hands shape into smooth oval patties with a slight dent in the center. Place on a plastic-wrap-lined tray.
6
Heat olive oil in a pan over medium heat, gently place the patties in, rotating the pan for even browning. Cook about 2 minutes, flip, then cook the other side about 1.5 minutes until both sides are nicely browned. It's fine if the inside isn't fully cooked yet.
7
In the pan with the sautéed onion, add olive oil and chopped garlic, sauté briefly, then add thickly sliced mushrooms and stir until coated. Pour in red wine and cook until the alcohol evaporates.
8
Add the chopped canned tomatoes, sugar, ketchup, bouillon cube, and water, stir well, and bring to a boil to make the sauce.
9
Return the seared patties to the pan, making sure they are nearly submerged in the sauce. Cover and simmer on low heat for 5–6 minutes, opening once midway to baste with sauce.
10
Check doneness by piercing with a bamboo skewer — clear juices mean it's cooked through. Taste and adjust seasoning with salt and pepper; if the sauce is too thin, add a bit of panko to thicken it.
11
Top the patties with your preferred amount of pizza cheese, cover, and cook for 1–2 minutes until the cheese melts.
12
Ladle the sauce and mushrooms into a soup dish, place the hamburg steak in the center, garnish with the string beans and red bell peppers, sprinkle parsley on top, and serve.