To make the sauce put all six of the first ingredients into a pot and cook until it starts reducing and thickening, mix cornstarch with a little water and turn it into a paste and add to the sauce. Cook for another 2-3 minutes then set aside.
Cut the chicken breast to about 1 1/2-2" pieces, do the same with onions and pineapple. If you are using wooden skewers make sure you put them in water for about 30 minutes so they don't burn on the grill. Alternate skewering chicken, onion and pineapple until you run out of the ingredients and then grill for 4-5 minutes on one side.Turn the skewers and start basting with the Teriyaki sauce. Grill until chicken is done and once removed from the heat baste the skewers one more time. Serve the leftover sauce on the side, we like to put some on the rice. Enjoy!
Notes
Leftover Teriyaki sauce keeps for about ten days kept in a jar and refrigerated.