• ¼ cup vegetable oil
• ¼ cup soy sauce (I prefer reduced-sodium)
• 2 Tbsp ketchup
• 1 Tbsp white vinegar
• ¼ tsp pepper
• 2 cloves garlic, finely minced
• make teriyaki sauce by combining all the ingredients listed. Set aside.

I got this recipe from   http://hiddenponies.com/2013/02/teriyaki-chicken-stirfry-with-homemade-teriyaki-sauce/