Cut chicken into your preferred cut. For my kids, I like it cut really small. If the kids are off visiting, I like it in bigger bites for the grownups. Heat your wok or large pan and oil of your choice. (I use olive oil, but some say it burns too easily. I've not had a problem with it.)
Put chicken and cashews in first, cook them about 1/2 way before adding your spices and veggies.
After everything has cooked through, there will be plenty of juices. I add my cornstarch very carefully directly to the pan, but I've had good luck, you could just premix it with water to avoid lumps. Cook until the sauce is slightly thickened.