Cook rice according to package directions. Fluff with a fork when done. Set aside.
Heat 1 tablespoon of olive oil on high heat. Season beef generously with salt and pepper. Add beef strips. Cook on one side undisturbed for 2 minutes, turn off and cook for 1 more minutes. Cook in batches if required. Set aside on a plate.
Heat additional oil if required. Add ginger and garlic and heat to medium high. Add asparagus, peas and fiddleheads with beef stock, sherry, tamari or soy sauce, toasted sesame oil, red pepper flakes and salt and pepper as required. Cook for 3-4 minutes.
Return beef to wok and heat until warmed through.
Optional, add cornstarch mixture and stir until thickened.
Spoon over cooked rice and serve.