01 -
Shape the ground chuck into loose 1/3-pound balls. Place them in the fridge for 30 minutes to firm up.
02 -
Slice the onions ultra-thin using a mandoline slicer. Press out extra water and keep them in the fridge until needed.
03 -
Cook the bacon until crispy and golden, then chop it into tiny bits.
04 -
In a bowl, combine mayo, ketchup, mustard, bacon pieces, Worcestershire, apple cider vinegar, crushed red pepper, and your preferred seasoning blend. Stir well!
05 -
Heat a griddle on high. Drizzle it with avocado oil, place chilled burger balls, then add onion slices on top. Smash the patties flat with a sturdy spatula and sprinkle seasoning generously over them.
06 -
After 3 minutes, when the patties have a crust, brush the mustard on top, flip them, and add sliced pepper jack cheese. Let them cook for 3 more minutes until the cheese melts.
07 -
Lightly toast buns on the griddle. Spread the bacon-mayo mixture on the bottom bun, stack two patties, top it off with more sauce, and finish with the top bun. Serve piping hot!