Put bacon strips on a parchment-line baking sheet; put another pan on top. Bake at 400 degrees, 10 minutes, then uncover and back 10 more minutes.
Lightly mix 6 ounces ground beef chuck with a big pinch of kosher salt. Form into a ball, then into a 3/4-inch-thick patty; make an indentation in the center. Heat a cast-iron skillet over medium-high heat; sprinkle the skillet with salt.
Cook the burger 4 to 5 minutes per side; top with 2 slices cheddar in the last minute of cooking (cover to melt). Serve on a sesame bun with the bacon.