Melt butter in a medium sauce pan over medium heat, then add the garlic and cook for 1 minute, until fragrant, stirring often.
Whisk in remaining sauce ingredients and raise heat to a simmer. Continue to heat, stirring often, until sauce has reduced by 1/3 or so before removing from heat. The sauce will continue to thicken as it cools. Do not overcook!
Chicken and Vegetables
Once sauce is started, use 1 tsp of the melted ghee/tallow/palm oil to grease the two baking sheets.
Season both sides of the chicken with house seasoning then place the pieces in a bowl or gallon size zipper bag and use a small ladle to add just enough of the sauce to coat the chicken (the remaining sauce will continue to reduce cook on the stove). Spread the sauce coated chicken pieces evenly across one of the baking sheets.
Place the veggies on the second sheet pan and drizzle remaining 2 tsp melted ghee/tallow/palm oil over all, then season generously with house seasoning, tossing a couple times to be sure they all get evenly coated.
Place the chicken and vegetables in the oven and roast for 20-25 minutes, turning halfway through (the veggies may only need 15-20 minutes). When you turn the chicken, brush it with a little more of the sauce - be sure you spoon some of the sauce into a separate bowl first so you don't contaminate the sauce pan with the brush you're using on the chicken.
Remove chicken and vegetables from the oven and turn the broiler on. Flip the chicken again, brush with sauce again, and place under broiler for 1-3 minutes to get that nice crisp on the surface. This step is optional, but highly recommended!
Sprinkle the chicken with sesame seeds, then serve chicken and vegetables over rice or noodles with a drizzle of sauce and a few sliced green onions.