In a small bowl, whisk together the sauce ingredients: cornstarch, soy sauce, chicken broth, sesame oil, rice vinegar, hoisin sauce, Sriracha, and black pepper. Set aside.
In a large skillet or wok, heat 2 tablespoons of oil over medium-high heat. Once hot, add the onion and cook until it becomes soft, approximately 4-5 minutes.
Reduce the heat to medium, then stir in the ginger and garlic. Stir briefly for about 15 seconds, then push them to the side of the skillet.
Increase the heat to high, then add the ground beef to the pan. Allow it to sit undisturbed for 30 seconds, and then use a wooden spoon or spatula to break apart the meat and cook until it is no longer pink.
While the beef is cooking, bring a large pot of water to a boil. Add the ramen noodles and cook them 1 1/2 minutes less than the package directions indicate. Drain and toss with 1 tablespoon of oil. Set aside.
Reduce the skillet heat to medium-high, then add the bell pepper, broccoli, and carrots. Let them cook until they become crisp-tender, stirring occasionally, for about 3-4 minutes.
Stir the sauce one more time, then add it to the skillet along with the ramen noodles.
Cook and toss everything together with tongs until the sauce has thickened and coated everything, taking approximately 2-4 minutes.
To serve, sprinkle green onion and sesame seeds over the dish. Enjoy!