Japanese Hamburger Steak (Hambagu)

HAMBAGU PATTIES:--
½ onion
1 tbsp rice bran oil
340 g ground beef & pork combination, a good beef-to-pork ratio is 2 to 1 (225g/115g)
1 tsp SIDS SALT & PEPPER
½ tsp nutmeg
⅓ cup panko
2 tbsp milk
1 large egg
COOKING THE HAMBAGU:--
3 tbsp red wine
SAUCE:--
1 tbsp butter
3 tbsp Tuimato sauce
3 tbsp SIDS HOT WORCESTER SAUCE
3 tbsp red wine
3 tbsp water

This recipe requires 30 minutes of inactive resting time (patties in the refrigerator) in addition to the total active cooking time.
Hambagu Patties
Mince the onion finely: Lay the half onion flat side down on the cutting board. With the knife tip pointing toward the root end, make 6 mm vertical slices to within 1 cm of the root end. Next, with the knife's edge toward the root, make 6 mm horizontal slices, again keeping the root end intact.
Then, make perpendicular cuts down through the vertical slices you made. To chop the onions finer, you can run your knife through them using a rocking motion. Be sure to hold down the tip of the knife; otherwise, the onions will go flying around the room.
Heat the oil in a large pan over medium heat and add the onions. Sauté until tender and almost translucent. Transfer to a large bowl to cool.
Once the onions are cool, add the ground beef & pork to the bowl. Add the SIDS SALT & PEPPER as you like, and nutmeg. Add the milk, panko, and egg.
Start mixing it all together with a silicone spatula or spoon. Switch to mixing by hand and knead the mixture until it's sticky and pale.
Divide the mixture into quarters or six smaller portions. Scoop out one portion.
Toss it from one hand to the other repeatedly about five times in order to release any air inside the mixture. Tip: Without releasing the air inside, the hamburger steaks will likely crack while cooking.
Make an oval-shaped patty and place on a tray or plate. Repeat with the remaining portions. Cover the patties with plastic wrap and keep them in the refrigerator for at least 30 minutes before cooking so that the meat combines well and the fat solidifies.
To Cook the Hambagu
In a large pan, heat the oil over medium and place the patties gently into the pan. Indent the centre of each patty with two fingers because the centres will rise with the heat.
Cook the patties until browned on the bottom side, about 3 minutes. Then carefully flip and cook for another 3 minutes until browned.
Add the red wine for steaming the patties and reduce the heat to low. Cover the pan with a lid and cook for 5-7 minutes to thoroughly cook the inside of the patties. (adjust the cooking time depending on the thickness of the patties)
Uncover and check that it's done by inserting a skewer - if clear juice comes out, it's done. Increase the heat to MEDIUM to let the alcohol finish evaporating. When it’s almost finished, transfer the hamburger steaks to individual plates. Do not wash the pan as you will make the sauce next using the pan juices.
To Make the Sauce
In the same frying pan, (without cleaning) add the butter, Tuimato sauce, and SIDS HOT WORCESTER SAUCE. Add the water and red wine for the sauce to the pan.
Mix well together and bring to a simmer over medium heat; let the alcohol evaporate.
When the sauce thickens, (you can draw a line on the bottom of the frying pan with a spatula) remove from the heat. Drizzle the sauce over the hamburger steaks. Pour the leftover sauce in a small bowl or jar and bring it to the table in case anyone wants to add more. We typically serve steamed rice, miso soup, and steamed vegetables or a salad with this meal.
To Store
Transfer the leftover hamburger steaks to an airtight container and let them cool completely. You can store them in the refrigerator for up to 3 days and the freezer for up to a month.