In a medium bowl, combine cubed chuck roll, salt, black pepper, thyme, and sliced garlic. Stir to coat. Cover and refrigerate to cure overnight.
2. Step
Prepare the sauce: in a small mixing bowl, combine the mayonnaise, ketchup, relish, vinegar, lemon juice, salt, and pepper. Whisk together. Refrigerate to bring flavors together.
3. Step
Using a stand mixer fitted with meat grinder attachment, grind the cured meat, layering in pieces of chopped bacon throughout. (Ensure the meat and grinder attachments are very cold before grinding! Recommended that you place it in the freezer for a few minutes just before using.)
4. Step
Lightly mix together the ground meat and then form into six, 3 ounce balls.
5. Step
To a hot, oiled, cast iron skillet, over medium/high heat - add the balls and allow to cook slightly. Using two spatulas layered on top of one another, press down on the burger to form into thin patties. Continue to cook until the underside has browned and caramelized.
6. Step
Flip the burgers and continue to cook until the second side just begins to brown. Top with cheese and remove from the skillet.
7. Step
To assemble: Spread the burger sauce onto both halves of a toasted potato bun. On the bottom bun, layer lettuce, tomato, and a sprinkle of salt. Add one burger patty, thinly sliced onions, then the second burger patty. Place 4 pickles onto the top bun and place on top of the burger.
