Gyudon Recipe / Japanese Beef bowl / 牛丼

Ingredients (Serves 2)
-Thinly sliced beef (rib eye or chuck) 250g
-Beef fat 20g (You can skip it if you cannot get it)
-Ginger (as peeled) 15g
-Onion 1each (130g)

[Kombu Dashi]
-Water 750ml
-Kombu (Dried kelp) 7g

-Sugar 20g
-Sake 90ml
-Soy sauce 30ml