Start by adding all your beef cuts onto a big sheet tray and mix them well. Transfer to the freezer for 30 minutes. Make your Shake Shack secret sauce while the beef cools.
In a medium bowl, add in all of your secret sauce ingredients and mix well until everything is evenly combined. Season with Kosher salt and black pepper to taste. Set aside.
Take the beef out of the freezer and grind it onto another sheet tray. Once all your beef is ground, make 8 (2 oz) loose balls and set aside.
Set a griddle or a flat top to medium high heat. Add your burgers and using a sheet of parchment paper and a burger press, smash your burgers real thin. Cook for 3 to 4 minutes or until the juices start to pool. Flip your burgers and add a slice of American cheese on top of each burger. Cook for a few more minutes until the cheese begins to melt. Remove from the heat and get ready to build your burgers.
Smear your burger buns with butter and toast them on the griddle or flat top for a couple minutes or until golden brown. Remove from the heat and set aside.
Start building your burgers. Onto a bottom bun, add your burger patty with cheese, lettuce, 2 slices of tomato and the top bun smeared with your Shake Shack secret sauce.