Heat oil in a pot over medium-high heat.
Sauté the beef until browned, then remove and set aside.
Add onion and cook until translucent.
Stir in garlic and carrot; cook for another 2-3 minutes.
Pour in the beef broth and bring to a boil.
Once boiling, reduce heat and add the noodles.
In a small bowl, mix soy sauce and cornstarch; slowly add to the pot.
Return the beef to the pot and let simmer for 5-7 minutes.
Adjust seasoning as necessary before serving.
Garnish with green onions and serve hot.