Cut the chicken pieces into bite-sized strips. Transfer to a bowl. Add the ‘marinade’ ingredients to the chicken. Toss them through. Cover the bowl and refrigerate overnight or for at least 2 hours.
Chop the broccoli into bite-sized florets. Use the main stem and side stalks too. Save the leaves for later.
Blanch the florets and stems in boiling water for 3 mins. Drain, run under cold water, and set aside.
Mix the ‘sauce’ ingredients in a bowl and set aside.
Heat the oil in a large pan. When the oil is hot add the chicken pieces to the pan. Keeping the heat on high, colour the chicken pieces on all sides. Do this in batches if your pan is not wide enough.
Test a piece and make sure the chicken is cooked through. Add the minced ginger and garlic into the pan and quickly sauté until they start to colour, about 45 secs.
Add the broccoli and the sauce. Continue cooking over a high heat tossing the chicken and broccoli with the sauce. Slightly saucy is nice here. Add a touch more water if necessary to get the right consistency. Scrape the caramelized bits from the bottom of the pan. All this is flavour that we want.
Take the pan off the heat and stir in the broccoli leaves and toasted sesame oil if using. The residual heat in the pan is enough to wilt the leaves slightly.
Best served hot with rice. Keeps refrigerated for up to 3 days and can be frozen for up to a month.