Make your stir fry sauce by combining sesame oil, sweet soy sauce, white pepper, corn starch, water and 1 tbsp of the light soy sauce in a bowl. Set aside.
Cut broccoli into florets.
Heat up a wok or non-stick skillet over medium heat. Add broccoli and a splash of water. Stir it around until the water starts to simmer, then cover wok with lid and let broccoli steam for 2-3 minutes or until it turns bright green. Remove broccoli from heat and set aside.
Heat up 1 tbsp olive oil in the same wok over medium heat. Add shredded seitan pieces and stir fry for 1 minute. Add 1 tbsp light soy sauce and stir fry until golden brown.
Deglaze the wok with Shaoxing wine, and add broccoli. Stir fry for 1 minute.
Add the stir fry sauce that was prepared earlier and stir fry everything for 2-3 minutes or until the sauce thickens to your liking.
Serve immediately with steamed rice.