Cut the fresh or thawed fillet into strips approx. 1 x 3 cm wide. Mix the ingredients for the marinade and marinate the beef in it for 30 minutes at room temperature. Cap the onions and garlic cloves at both ends, peel and roughly cut into pieces. Wash and clean the remaining vegetables and cut into bite-sized pieces. Mix the ingredients for the sauce together, except for the leftover marinade.
Strain the beef strips and add the remnants of the marinade to the sauce. Whisk the egg white with the tapioca flour until homogeneous and mix in the beef strips. Heat the peanut oil in a wok, add the meat strips and stir-fry for 2 minutes. Remove the strips from the wok with a slotted spoon and keep them ready.
Put the sunflower oil in the wok and let it get hot. Add the onions and garlic cloves and stir-fry until the onions are translucent. Add the remaining vegetables and stir-fry for 2 minutes. Deglaze with the sauce and simmer for 1 minute.
Remove from heat, mix in the strips of meat, distribute on the serving plates, serve with rice and enjoy.