Whisk together orange juice, barbecue sauce, soy sauce, Sriracha sauce, minced garlic, 2 tablespoons of cornstarch and sesame seed oil, Pour over the roast in a slow cooker.
Cook on high for 5-6 hours or low for 7-8 hours.
Remove the roast to a pan with sides and transfer the sauce a saucepan.
Shred the roast and return to the slow cooker.
Mix together 2 tablespoons of cornstarch and cold water and whisk it into the sauce. Bring the sauce to a boil while whisking and cook until thickened.
Pour the sauce over the beef. Serve over rice or noodles. Garnish with sesame seeds and sliced green onions.