- Slice flank steak against the grain. 
- In a bowl, mix together ingredients for the marinade. Add sliced beef and mix until coated. Let marinade in the fridge for 30 minutes. 
- Slice onion and spiralize zucchinis. 
- In a mixing bowl, add soy sauce, coconut sugar, ginger powder, chilli powder, garlic powder, cornstarch and water. Mix until combined. 
- Heat up 1 tbsp oil in a large nonstick skillet over medium heat. Add onion and stirfry for 1 minute. 
- Increase heat to high, add marinated beef and let sear until golden brown, about 1-2 minutes. 
- Remove beef from heat and transfer to a plate. 
- Reduce heat to medium and add the soy sauce mixture. Cook for 1-2 minutes or until it has thickened to the consistency of syrup. Add beef and spiralized zucchini to skillet and stir. Cook for 1 minute or until zucchini is cooked to desired doneness. 
- Remove from heat and serve immediately. Garnish with sesame seeds. Enjoy!