Preheat the grill to 350 degrees F and set it up for indirect heat with a handful of wood chips or pellets added for smoke, or preheat the oven to 350 degrees F if baking indoors.

Set a cream cast iron skillet over medium heat on the stovetop and add the ground breakfast sausage, diced onion, and diced jalapenos.

Cook, breaking the sausage into small crumbles with a pale wood spoon, for about 8 minutes, until no pink remains and the onion has gone soft and translucent.

Tilt the skillet and spoon off the excess fat, leaving the sausage, onion, and jalapeno behind in the pan.

Scatter the cubed Velveeta, cubed cream cheese, and shredded Monterey Jack over the sausage mixture so the whole surface of the skillet is covered.

Pour the diced tomatoes with green chiles, undrained, over the cheese, then sprinkle with the garlic powder and black pepper.

Set the skillet, uncovered, on the indirect side of the grill grates (or on the center oven rack) and cook for 45 to 60 minutes.

Stir the queso every 15 minutes with the wood spoon, scraping the bottom of the skillet, until every cube has melted and the dip looks glossy, smooth, and free of lumps.

Lift the skillet off the heat and let the queso rest for 5 minutes; it will thicken slightly as it sits.

Scatter the chopped cilantro and sliced jalapeno over the top, then carry the skillet straight to the table with a bowl of tortilla chips alongside.