Grate or finely mince onion, for a total of 3 tsp.
Add 2 tsp of breadcrumbs and 1 tbsp of milk to a small bowl and mix them together.
Finely chop beef fat, for a total of 1-1.5 tbsp. In addition, cut a small piece of beef fat to use later for pan-frying the patty.
Place 1/3 pound of cold ground beef in a chilled bowl. Add 1/4 tsp of salt, and rub well into the meat, until it becomes slightly sticky. If you have plastic gloves like I am using in the video, this helps keep the mixture cool.
Add a pinch of salt, 1/4 tsp each of black pepper and nutmeg, the moistened breadcrumbs, the chopped beef fat, 3 tsp grated onions, and 1 tsp of beaten egg to the salted ground beef. Mix all together well.
Then form the mixture into a round patty, trying to remove any air pockets by gently tapping it several times with your palm. Finish shaping the patty, making sure the surface is very smooth. Then create a little dimple in the center. Keep the prepared patty cool in refrigerator until you are ready to cook it.
Add a small piece of the beef fat to a frying pan and heat on high. Heat until you see a little smoke rise from the pan.
Gently place the patty in the pan and cook for 2 minutes on one side. Flip it over, and cook for another 2 minutes. Then cover with a lid, reduce the heat to medium, and cook for 3-4 more minutes. Turn off the heat and let it rest covered in the pan for another 3-4 minutes.
Take out the hamburg steak, discarding the beef fat.
Before making the sauce in the same pan, lightly remove some of the remaining fat, using a paper towel.
Add 1 tbsp each of red wine, ketchup, and Worcestershire sauce to the pan, and stir over medium heat. Simmer until everything is well mixed and the sauce begins to thicken.
Pour the sauce over the hamburg steak. It's ready! We hope you enjoy your "TOKYO FLAVORS, NEW YORK STYLE" meal! Itadakimasu!