Mmmmmm.... marinated 18 hrs and cooked at 400 until 160, and let it rest until 164 (about 10 minutes). Made a sauce with the marinade based on an onion puree sauce. Dang!!! This was slap-yo-momma melt-in-your-mouth good.
The recipe for the onion puree sauce was in a book apparently meant for restaurant quantities.
"Start by peeling and sweating 5lbs of onions"....