Cook edamame pasta in boiling water according to package directions, drain, and set aside.
In a bowl, toss the sliced flank steak with cornstarch until evenly coated.
Heat sesame oil in a large wok or skillet over high heat.
Add the beef to the wok in a single layer and sear until browned, approximately 2 minutes per side; remove beef and set aside.
In the same wok, add minced garlic and grated ginger, sautéing for 30 seconds until fragrant.
Whisk in soy sauce, water, and brown sugar, bringing the mixture to a simmer.
Add broccoli florets to the sauce and cook for 3 to 4 minutes until tender-crisp.
Return the cooked beef and pasta to the wok.
Toss all ingredients together for 1 to 2 minutes until the sauce thickens and coats the noodles and protein.
Garnish with sliced green onions and red pepper flakes prior to serving.