01 -
In a small bowl, stir together mayo, tomato sauce, Worcestershire, garlic powder, a little pepper, and salt until smooth and creamy.
02 -
Take the minced beef and divide it into eight portions weighing about 85 grams each. Lightly roll them into balls without pressing too hard.
03 -
Get your cast-iron skillet or griddle sizzling hot—450° to 500°F—whether you're using a stovetop or barbecue.
04 -
Cut some small parchment paper squares (about 7.5 cm) so they’re ready to help press the patties.
05 -
Add oil to the hot skillet and drop the onions into eight small heaps, about a quarter-cup in size.
06 -
Scatter thin slices of chili on top of the onion piles. Sprinkle with some kosher salt and pepper for added taste.
07 -
Let the onion-chili piles cook for 30 to 60 seconds without touching them, so they develop a little brown color.
08 -
Put one of your beef balls on each onion pile and cover it with one of the parchment paper squares.
09 -
Press the beef balls firmly with the back of a spatula or burger tool, flattening them into super-thin patties about 10 cm wide.
10 -
Sprinkle a bit more salt and pepper on top of the freshly smashed patties.
11 -
Cook the patties for 2 to 3 minutes without moving them. They'll crisp up around the edges and get golden.
12 -
Gently flip the patties over, making sure the onion-chili topping is now on top.
13 -
Set cheddar slices on four of the patties and cook another 1.5–2 minutes until golden and bubbly.
14 -
Stack a plain patty on top of one that has melted cheese, making it a two-layer burger.
15 -
Spread the sauce on toasted buns, assemble the burgers, and serve them hot right away.