Grilled up the chicken on Saturday. It turned out delicious. I grilled with lump charcoal, which I do not have much experience with, and because of that had a hard time telling how hot everything was going to be, and how long it would stay hot. I ended up doing more direct grilling that I thought I would because the heat was lower than expected. I guess I'll just have to use lump charcoal more often to get used to it. I think total cooking time ended up being an hour.
However the chicken turned out delicious. Moist and flavorful. I ended up straining out the onions and jalapeños then boiling and reducing the marinade because I couldn't stand to just throw it away. The onions and jalapeños sat on top of the chicken most of the time that it grilled. I basted the chicken once with the reduced sauce. I took some more of it and used it as a hot dressing for a lettuce, corn and black bean salad, because that popped into my head. The lettuce of course wilted a bit, but tasted ok. The corn and black beans covered in the sauce was great.
This really is a great recipe, and my friends who ate over commented more than once about how good it was. Everyone started with knives and forks, but by the end everyone was using their hands.
On Grill:

Finished:

Plated with braised kale and the corn bean salad thing: