In a large bowl, whisk together the beef broth, soy sauce, brown sugar, garlic, oil, vinegar, ginger, Sriracha, onion powder and white pepper.
Put the roast in a 5 or 6 quart slow cooker. Pour the broth mixture over the beef.
Cover and cook on low for 7 to 8 hours or on high heat for 3 to 4 hours, or until the cubes of meat are very tender but still retain their shape.
In a small bowl, whisk together the cornstarch and water. Stir the mixture into the broth in the slow cooker. Cover and cook on high for an additional 30 minutes, or until the sauce has slightly thickened.
Serve immediately, garnished with green onions and sesame seeds if desired.
Notes
If you are preparing this recipe as gluten free, be sure to use GF versions of beef broth and soy sauce.