If you want to render the kidney fat cut it into small bits or mince it in a food processor.
Then, put it into a pot or big pan on low heat and wait for all the fat to get out while stirring occasionally.

You can see that it's done when there is clear fat on the bottom with crispy bits on top.

Now, you can remove these floating bits by pouring all content through a cheesecloth or fabric into another pot.
When the fat is cooled, pour it into mason jars and keep them in the fridge.

The method in this recipe works with nearly any type of meat, but best with cuts that contain fat & some gristle like beef shank or ham hock.

You may also enhance the sauce by deglazing the onions with red wine and let it cook for a minute before adding the meat stock.

Take care not to add too much salt, because the soy sauce is pretty salty already.

As a side dish, I like to simply cook some eggs or vegetables.

This sauce goes very well with the chicken heart tuna meatballs which I made simultaneously.

Of course, you could also simply use it to go with your asparagus or other types of vegetables, like broccoli, cauliflower or mushrooms.

Attention: To prevent the goulash from scorching, don't forget stiring it or adding some water from time to time.

The goulash is perfect when the peppers, tomatoes and onions all dissolved into one mixture and when the meat is soft.

It tastes best after 1-2 days in the fridge! In addition, I like to eat it with some cream cheese or zoodles.

Basically, you can use as much cheese as you like, take less water or let the soup cook a while longer to make it as thick and creamy as you desire.

It is perfect, when the meat seperates from the bone by itself.

Kassler  is the name of a cured and smoked cut of pork. Its roots are in the German cuisine. Pork necks and loins are the most commonly used cuts, although ribs, shoulders and bellies can also be used. In addition, kassler is often served with sauerkraut.