Cook ramen noodles according to package directions, discard seasoning packets, drain, and toss with sesame oil.

Whisk together soy sauce, oyster sauce, brown sugar, rice vinegar, and cornstarch in a small bowl to make sauce.

Heat oil in skillet and sear beef strips until browned but not fully cooked through. Remove and set aside.

In the same skillet, sauté garlic and ginger until fragrant, then add broccoli and stir fry until tender-crisp.

Return beef to skillet, add sauce, and simmer until thickened and beef is cooked through.

Add ramen noodles to skillet and toss everything together until coated in sauce. Garnish with sesame seeds and green onions before serving.