Heat a small sauce pan on medium high and add 1 tsp of sesame oil. Once hot, add the sesame seeds and cook until golden brown.
Mix in the soya sauce, 2/3c water, apple cider vinegar, brown sugar, honey, remaining sesame oil, grated/minced garlic and grated/minced ginger. Whisk until the sugar has dissolved and the sauce comes to a boil. Reduce to a simmer and cook for five minutes.
Whisk the cornstarch and 3 tbsp cold water and pour slowly into the sauce while whisking. Cook for a couple more minutes, until the sauce is thick. Set aside to cool completely.
Once cool, toss the sauce with the chicken thighs in a large ziplock bag and marinade for at least 2 hours, preferably overnight.
Preheat oven to 375°. Dump the ziplock bag out into a baking dish including the marinade. Bake for 30 minutes or until the internal temperature reached 180°. Serve hot.