Heat a 2 teaspoons of the oil in a wok or large non-stick pan over high heat. Add half the chicken and spread out as evenly as possible in the pan. Allow it to sit and brown slightly for 30 seconds to 1 minute before stir frying quickly it in the pan to brown lightly all over. Transfer to a plate and set aside. Repeat with remaining chicken. Set aside.
Heat remaining oil in pan until hot. Add the onion and stir fry for 1 minute. Add the the curry powder and sugar and stir until combined. Return all the chicken to the pan and stir fry for a further 1 minute.
Add the peanut butter and Jimmy's Sate Sauce (start with 1 tablespoon for a milder heat then add according to taste) and stir to coat well. Slowly start adding water until you reach a consistency you like (I usually add around ¾ cup water)
If using broccoli, add it now and stir to combine. Stir until throughly heated through. Serve with steamed white rice. Garnish with spring/green onion curls if desired.