Cut 3 slices bacon in half, crosswise.

Set aside 2 leaves of romaine lettuce or finely shred 1 cup of iceberg lettuce.

Slice 1 ripe tomato

Set aside 2 slices of quality white bread.

Heat a cast-iron skillet over medium-low heat.

Add the bacon and weigh it down with a bacon press, a skillet, a masonry trowel, or a foil-wrapped brick to keep it flat as it cooks.

Cook the bacon until lightly browned on the first side, about 5 minutes.

Flip the bacon over, weigh it down again, and continue cooking until the bacon is browned, about 3 minutes longer.

Transfer the bacon to a paper towel–lined plate and set aside.

Toast the bread in the bacon fat, swirling and flipping until both sides are evenly browned.

Lay the toasted bread on a work surface and spread mayonnaise on one side of both pieces.

Place the lettuce on one slice of bread of bread.

Lay 3 slices of bacon next to each other on the lettuce.

Lay the remaining 3 slices of bacon next to each other on top of the first layer of bacon, but in the opposite direction.

Lay the tomato on the bacon.

Sprinkle the tomato with Kosher salt and freshly ground black pepper.

Close the sandwich and cut it in half diagonally into triangles.