In a large pot, combine the chicken broth, soy sauce, mirin, sake, sugar, ginger, garlic powder, onion powder, and black pepper. Bring to a boil over medium-high heat.
In a separate skillet, heat the vegetable oil over medium-high heat. Add the ground beef and cook for 5 minutes, stirring occasionally, until browned. Add the shrimp and cook for an additional 2 minutes.
Add the beef and shrimp to the pot with the broth. Add the green onions, mushrooms, and cornstarch. Simmer for 8-10 minutes until the soup has thickened.
Stir in the sesame oil and serve hot.
Interesting Facts
This soup is a popular dish in Japanese steakhouses.
The soy sauce, mirin, and sake are all key ingredients in this soup, as they give it its signature flavor.
The cornstarch helps to thicken the soup, making it rich and creamy.