In a medium bowl stir to combine soy sauce, sriracha, cornstarch, sesame oil, and 1 tablespoon water. Add beef, toss to coat, and marinate for 15 minutes.
In a very large skillet or wok, heat 1 tablespoon oil over high heat until it begins to glisten. Add broccoli and bell pepper and cook, stirring frequently, until crisp-tender, about 2 minutes. Add pineapple and cabbage and cook, stirring, 1 minute more.
Transfer vegetables to a bowl and wipe out skillet or wok. Add remaining 1 tablespoon oil and heat until shimmering.
Add beef to skillet or wok and cook, stirring occasionally, until browned, about 2 minutes. Add vegetables back to pan and toss everything together.
Served garnished with green onion.