Marinade: Add everything except for the chicken to a large bowl and whisk until completely combined.
Place the chicken into the marinade and thoroughly to ensure the chicken is completely covered.
Place plastic wrap over top of the bowl or transfer to a plastic zip bag and marinate for at least 12 hours or up to 48 hours.
Sauce: Right before you are ready to start cooking add the sauce ingredients together to a medium-size saucepot and cook over low heat until the butter has melted in and the sauce is hot. Set aside.
Preheat the grill in 3 sections with one side being hot (550°+) the middle section over medium heat (350° - 400°) and the last section over low heat (300° - 350°). See Chef notes if this is not an option.
Once the chicken is done marinating transfer to a platter lined with parchment paper to make it easy to place right on the grill without marinade going everywhere.
Add the chicken skin side down onto the hot portion of the grill and cook for 3-4 minutes. See video to keep from burning.
Move the chicken to the middle portion of the grill where the heat is on medium without flipping it over and cook for 5-6 minutes.
Flip the chicken over on the same area on the grill and immediately baste with the BBQ sauce and cook for 5-6 minutes.
Turn the chicken over and transfer it over to the low hear area on the grill and immediately baste with BBQ sauce on the bottom side of the chicken and cook for 3-4 minutes.
Lastly, flip the chicken over, baste 1 more time and cook uncovered for 20 to 25 minutes, covered for 15-20 minutes, or in the oven at 350° for 15-20 minutes or until the chicken reaches 155° to 160°.
Remove the chicken and let rest for 3-5 minutes.
Serve with more BBQ sauce and an optional garnish of chopped chives, green onions, or parsley.
Notes
Make-Ahead: You can make this up to 30 minutes ahead of time, cover with foil and keep in the oven at 200° until ready to serve.How to Store: Cover and keep the grilled BBQ chicken for up to 4 days in the refrigerator. You can freeze this covered for up to 3 months. Thaw in the refrigerator for 1 day before reheating.How to Reheat: Place the desired number of grilled BBQ chicken pieces on a sheet tray lined with parchment paper and cover with foil and bake at 350° for 15 minutes. Remove the foil and cook for a further 10 minutes or until hot.All parts of the chicken are good for this recipe, so feel free to use a combination or just 1 cut like drums or thighs.If there are a lot of flames coming through the flames, tone them down with a few ice cubes in the places where they are most prevalent.Substitute the fresh onion in the marinade with 1 ½ tablespoons of onion granules.You can swap out the fresh garlic for 1 tablespoon of garlic granulesThis same grilling and marinating technique can be applied to pork chops.If you do not have the option to split the grill into different heat sections then only heat 1 side of the grill and leave the other side completely off and let it cook by indirect heat with the grill covered.