Preheat the oven to 375°F. For an 18-piece batch of this chicken, have a large (at least 9x13") oven-proof dish or a parchment-lined baking tray at the ready.

Finely chop the onion and set it aside.

Remove the skin from the chicken thighs and discard.

Heat the olive or grapeseed oil over medium-high heat in a large pan (I use a 10-inch pan with sides that are about 3" high) or skillet. Working in batches so as not to crowd the pan, sprinkle the chicken with the salt and pepper and sauté it until it's nicely browned on both sides (this will take about 10 minutes per batch — see Note). Remove the browned chicken to a large bowl.

Turn the heat down to medium and add the chopped onion to the pan. Stir it around until it starts to become translucent. Turn off the heat and add about half of the barbecue sauce to the pan. Stir well, scraping the pan to loosen the bits stuck to the bottom.

Spread the onion/sauce mixture on your lined baking tray or in the bottom of the baking dish. Add the chicken, turning each piece in the mixture to coat it well. Then spread the other half of the barbeque sauce evenly over the chicken.

Roast the chicken in the pre-heated oven for about 40 minutes, turning at the 15- and 25-minutes marks. The top of the chiken should be facing up for the last 15 minutes of roasting. By this point, the chicken should be completely cooked (see note).

At the end of the 40 minutes, turn the broiler to high. Once it's come on, broil the chicken for about 5 minutes, or until the sauce is bubbling and blistering, and beginning to char. Watch it like a hawk, because there's a short window between appealingly charred and burned.

When you serve it, spoon any of the onion/sauce mixture from the bottom of the tray/pan over the chicken. It's too good to let it go to waste.

Get out the napkins and get ready for compliments!