Original recipe here:
https://cooking.nytimes.com/recipes/1017398-japanese-style-beef-stew
It took like 2 hours of simmering to get the beef tender. We decided to wait until the beef was basically tender before adding the sweet potato.
Not sure if we should have added more liquid or not ... tbd
Apparently the name for this stew in japanese is Nikujaga
Comments say: Simple rule of 1 hr/1 lb chuck. Low heat and slow.
Next time: leave the lemon peel out because it can make the broth bitter.