Cook the noodles according to package instructions, drain and set aside.
In a large skillet or wok, heat vegetable oil over medium-high heat.
Add ground beef and cook until browned and cooked through, breaking it apart as it cooks.
Add garlic and ginger, sauté for 1-2 minutes until fragrant.
In a small bowl, mix soy sauce, brown sugar, and water or broth.
Pour the sauce mixture into the skillet with the beef. Stir and cook for 3-5 minutes until the sauce thickens slightly.
Add crushed red pepper flakes if desired and stir to combine.
Toss cooked noodles into the skillet and mix until noodles are well coated with the sauce and beef.
Garnish with sliced green onions and sesame seeds before serving.
