Steps

1. Finely mince 1/4 onion for the patty. 【Here's the trick!】 If the minced pieces are too large, they won't mix well with the meat, so chop them as finely as possible.
   🕒 01:33
2. Cover the minced onion for the patty with plastic wrap and microwave for 1 minute on 600W. Let it cool to room temperature. 【Here's the trick!】 Heating removes the sharpness and brings out sweetness.
   🕒 02:00
3. Thinly slice 1/4 onion for the sauce along the grain.
   🕒 02:28
4. Trim the tough ends off 50g shimeji mushrooms and separate them.
   🕒 02:43
5. Place 250g ground mixed meat in a bowl and sprinkle with salt and pepper to taste.
   🕒 02:58
6. Without adding any other ingredients, knead the meat until it becomes sticky. 【Here's the trick!】 By making the meat fats adhere to each other, the patties will be less likely to break apart during cooking and will retain their juices.
   🕒 03:05
7. Add 3 tbsp breadcrumbs, 1 egg, the cooled minced onion, and 1 tbsp mayonnaise to the kneaded ground meat. Mix thoroughly until sticky. 【Here's the trick!】 Adding mayonnaise makes the patties very soft, fluffy, and juicy.
   🕒 03:33
8. Lightly grease your hands with vegetable oil, divide the patty mixture into 3 portions, and shape them into hamburg patties, removing any air bubbles. Make a slight indentation in the center so it cooks through evenly. 【Here's the trick!】 Hamburg steaks shrink when cooked, so it's good to make them slightly larger.
   🕒 04:05
9. Lightly coat a frying pan with vegetable oil to taste and heat over medium heat.
   🕒 04:58
10. Place the shaped hamburg patties in the heated frying pan. Add the thinly sliced onion for the sauce and the shimeji mushrooms in any available space. 【Here's the trick!】 The onions and mushrooms will absorb the delicious flavors from the meat, making them tasty.
    🕒 05:11
11. Reduce the heat to medium-low and cook for about 3 to 4 minutes.
    🕒 05:42
12. Once the bottoms of the hamburg patties have a nice brown color, flip them over.
    🕒 06:02
13. Reduce the heat to low, cover with a lid, and steam for 3 minutes.
    🕒 06:13
14. Remove the steamed hamburg patties from the frying pan.
    🕒 06:37
15. Turn off the heat in the same frying pan. Add 3 tbsp ketchup, 3 tbsp medium-thick sauce, 1 tsp sugar, 1/2 tsp granulated consommé, 10g salted butter, and 200ml water.
    🕒 06:46
16. Turn the heat back on and warm the sauce while stirring until it starts to simmer.
    🕒 07:02
17. Once the sauce is simmering, return the hamburg patties to the frying pan and spoon the sauce over them.
    🕒 07:16
18. Cover with a lid and simmer over low heat for 5 minutes.
    🕒 07:31
19. After 5 minutes, remove the lid and flip the hamburg patties.
    🕒 07:42
20. Cover with a lid again and continue to simmer over low heat for 5 minutes.
    🕒 07:55
21. After 5 minutes, remove the lid and flip the hamburg patties.
    🕒 08:00
22. Spoon sauce over the hamburg steaks and continue to simmer, flipping them approximately every 5 minutes. 【Here's the trick!】 This prevents burning and results in a delicious finish.
    🕒 08:16
23. Finally, cover with a lid and simmer over low heat for 5 minutes.
    🕒 08:26
24. Once the sauce has thickened and coats the meat, your soft and juicy stewed hamburg steaks are ready.
    🕒 08:33