Cook the frozen udon noodles according to package instructions. Drain the noodles and set them aside.
In a small pot, add 1 tablespoon of oil and heat over medium heat. Add minced garlic and sliced onion. Saute for 1-2 minutes, or until fragrant. Add mushroom and saute for another 1-2 minutes until soft.
Add soy sauce, chicken broth, and beef slices. Bring the soup to a boil. Once boiling, bring it down to a simmer and cover the pot with a lid. Let is simmer for 3 minutes.
Add milk or heavy cream and Japanese curry roux. Stir well until the curry roux is dissolved.
Add cooked udon noodles. Garnish with chopped green onions. Serve hot and enjoy!
