Ultra-crispy, onion-crusted smash patties stacked on buttery, griddled potato buns with molten cheddar and a tangy, umami-packed fancy sauce. Every bite hits with crunchy edges, sweet caramelized onion, and rich, saucy depth.
Heat a griddle or heavy iron pan to medium heat.
Swipe a thin layer of mayonnaise over the tops of the potato buns and place them on the griddle. Cook until golden brown, then smash them gently to flatten. Toast both sides until golden; set aside to cool slightly so they hold their shape.
Form the ground beef into 2 oz balls. Plan for 2 patties per burger (8 patties total).
Increase griddle heat to high. Create small piles of razor-thin sliced onions on the griddle—one pile per patty.
Place a beef ball on each onion pile and smash very thin using a burger press and wax/parchment paper. Season with Meat Church Blanco to taste.
Cook until the edges are deeply browned and a crust forms and the onions caramelize into the meat.
Flip the patties. Immediately top each patty with a slice of cheddar and cook until the cheese is melted and slightly crispy at the edges.
Stack two patties on each bottom bun. For this build, place the buns so the inside faces outward as noted in the recipe.
Make the Fancy Sauce: In a bowl, combine mayonnaise, ketchup, fish sauce, Texas Pete’s hot sauce, and a pinch of Blanco. Stir until smooth.
Spoon fancy sauce over the stacked patties, top with the remaining buns, and serve immediately.