2 small steaks (sirloin or ribeye)
2 yellow onions (peeled and finely chopped)
2 tsp soy sauce
2 tbsp sake (optional)
4 tbsp water
½ tsp sugar
1 tbsp butter
1 tsp potato starch (dissolved in 1 tbsp water)
2 tbsp vegetable oil
freshly ground black pepper (to season)
salt (to season)
2 portions cooked japanese rice (to serve)
fresh parsley to garnish (optional)