Add butter to a pan, and sauté the onions once the butter has melted. After sautéing, they will cool faster if you make an opening in the center as shown in the photo.
Add in 4 shakes of salt and 3-4 shakes of nutmeg to the ground meat, and mix together thoroughly by hand. Mix until it all sticks together.
Place the ○ in milk, and thoroughly mix together. It holds everything together.
Mix Steps 1-3 and an egg together.
Using your hand so that it all mixes together well, knead by pinching the meat between your fingers so that it squeezes out.
Once it has all stuck together, lump it all together,and strike it against the bowl several times to remove the air pockets. Divide into 4 equal portions and mold into patties.
Add oil, and cook both sides over medium heat. When placing the burgers in the pan, press down on the center to flatten them. (The hamburgers will eventually plump back up).
Cover with a lid and cook through at a medium heat, flipping them over after 2-3 minutes. After 2 minutes has passed, add sake and lower the heat to steam.
Stick a toothpick into the center of the burgers, and it is done if the juices run clear. Cook for a little longer if red juices come out.
Make the sauce. Wipe the pan that you used for the burgers clean with a paper towel, and add in all of the remaining ingredients aside from the wine.
Once the sauce has reached a boil, add in the wine and bring it to a boil again, then you are done.
Story Behind this Recipe
I've made several different kinds of hamburgers, but my children love simple hamburgers the best. Part of the reason they don't get sick of them is because I make it with an original sauce. It is much more delicious than any old sauce.
Make sure to thoroughly knead in Step 5. Make sure to get rid of all the air pockets in Step 6.