Step 1

Mix the ingredients together for the Shack sauce and, if serving, bake crinkle cut fries in the oven according to package directions.

Step 2

Add salt & pepper to ground beef and mix together in a large bowl. Form 4 even round balls of beef.

Step 3

Meanwhile, heat a large skillet over med-high heat. Add balls, then press down to "smash" into patties. Cook for 3-4 minutes, then flip and cook another 2 minutes. Add 1 cheese slice to each burger, then place lid over the skillet to let the cheese melt and remove from heat.

Step 4

Remove burger patties from skillet, and wipe the pan clean with a paper towel. Butter the potato buns. Place in skillet, then add back to med-high heat, waiting until buns are lightly toasted, about 2 minutes.

Step 5

Add burger patties to each bun, then top with tomato, lettuce and Shack sauce. Serve alongside crinkle cut fries if desired, then serve and enjoy!