The original Japanese cooking technique of "Teriyaki" is braising not really grilling. "Teri" 照り means glossy surface or luster and "Yaki" 焼き means grilled but "Yaki" in Japanese could mean braised as in "Sukiyaki". So, any dish braised in a sauce (usually soy sauce based with sugar) until the sauce is reduced and thick (due to the sugar content) and coats the surface of the food items is called "Teriyaki" either meat or fish.
I then poured in "Teriyaki sauce"* and put the lid on for a few minutes (in this case, I really did not need to cook the chicken further). With the lid off, I turn up the flame and reduced the sauce until it became thick; clinging to the surface of the chicken giving "teri" or luster to the surface. Just to be slightly different, I sprinkled Chinese 5 spices (or Japanese "sansho" 山椒powder) to finish.
*You could use a bottled one but I just use a mixture of soy sauce and mirin (about 1:1).
Since this was made from leftover grilled salted chicken, it took less than 5 minutes to make. This was a sort of cannot-go-wrong type of small dish if not exciting. The cinnamon flavor of the Chinese 5 spices came out rather prominently. If you do not like this, stick to "Sansho" powder.