Begin by cooking the rice noodles according to the package instructions. Drain and set them aside, ensuring they don’t stick together.
Thinly slice the top sirloin against the grain to keep the beef tender.
While the noodles are cooking, slice the red bell pepper, onion, and carrots. Halve the broccolini for even cooking.
In a bowl, whisk together the soy sauce, minced garlic, grated ginger, brown sugar, fish sauce, rice vinegar, sesame oil, and cornstarch to create the stir-fry sauce.
Heat 2 tablespoons of canola oil in a large wok or skillet over medium-high heat until shimmering.
Add the sliced beef to the hot wok in a single layer. Let it sear for about 2-3 minutes without stirring, then toss until browned and just cooked through. Remove the beef from the pan and set aside.
In the same wok, add the sliced onion, carrots, red bell pepper, and broccolini. Stir-fry for about 4-5 minutes until they are tender-crisp.
Return the cooked beef to the wok and pour the sauce over everything. Toss to combine, ensuring the beef and vegetables are coated in the sauce. Cook for an additional 2-3 minutes until the sauce thickens slightly.
Finally, add the cooked rice noodles to the wok, gently tossing everything together until well mixed and heated through.
Serve your Beef Noodle Stir Fry hot, garnished with optional sesame seeds and sliced green onions for an extra pop of flavor and color. Enjoy!
