Season the thick patties with salt and pepper, and let them rest while the coals come up.
Caramelize the onions low and slow. For the queso: warm the half & half, steep the jalapeños, and melt in the cheese. Finish with Dijon and Worcestershire. No roux. It thickens as it cools.
Get a cast iron skillet screaming hot over the coals. Lay the patties beef-side down so they cook in their own tallow. Press lightly, and flip once.
Rest the burger like you would a steak.
Build it: toasted bun, pickles, onions, bacon if you like, then a generous pour of queso.
Recipe by Neal Williams of Pellets and Pits. Watch the full cook, including the jalapeño burger built from the same patties.