In a large pot over high heat, add oil and onions. Cook until onions are translucent (about 5 minutes).
Add beef and cook for 5 minutes or until cooked through. Add potatoes and carrots and cook for another 3 minutes. Add sake, dashi stock, soy sauce, sugar and mirin, and cook for 20-30 minutes, or until vegetables are tender). Serve with a side of Japanese rice
Serve with a side of Japanese rice
You can adjust the flavor by adding a little more sugar or soy sauce depending on your preference (if you like sweeter or saltier).