Follow these simple steps to create a delicious plate of Mongolian Ground Beef Noodles:

1. Cook the Noodles: Boil egg noodles according to package instructions until al dente. Drain and set aside.
2. Brown the Beef: In a large skillet or wok over medium-high heat, add sesame oil. Once hot, add the ground beef and cook until browned, breaking it up with a spatula (about 5-7 minutes).
3. Add Vegetables: Stir in the sliced onion, garlic, ginger, broccoli, and bell peppers. Cook for an additional 3-5 minutes until vegetables are tender-crisp.
4. Prepare Sauce: In a small bowl, combine soy sauce, oyster sauce, red pepper flakes, and cornstarch. Mix well to form a sauce.
5. Combine Ingredients: Pour the sauce over the cooked beef and vegetables, stirring to coat evenly and simmer for 2-3 minutes until sauce thickens.
6. Add Noodles: Gently fold in the cooked egg noodles until well combined, ensuring that everything is coated in the sauce.
7. Serve: Remove from heat and transfer to serving bowls. Garnish with chopped green onions and sesame seeds.
8. Enjoy: Serve warm and enjoy the burst of flavors!

Following this instructional guide allows you to easily recreate the delightful flavors of Mongolian Ground Beef Noodles at home.