Add mayonnaise, ketchup, sriracha (optional), Worcestershire Sauce, dill pickle juice, sweet relish, mustard and whisk thoroughly.

Taste for seasoning and add salt and pepper if desired. Set aside until later use.

Slice the onions into two to three inch round slices. One large onion should yield about four to five round slices of onions. Do not separate the onion slices, this will act as the bun for the Flying Dutchman burger patties.

In the cast iron skillet on medium to high heat, place one tablespoon of butter in the pan.

Once the butter begins to bubble, place each onion ring into the pan and season both sides with salt and pepper.

The caramelizing process will happen fairly quickly (about 3-5 minutes). Be sure to only flip the onion rings once, ensuring each side is seasoned with salt and pepper.

The onions are cooked through because the color will become golden brown and the onions will begin to soften and wilt.

Set the caramelized onions aside until later use. Be sure to not clean the pan, there's flavor there that will be used when preparing the burger patties.

In a large bowl, add the ground beef.

Portion out each burger patty into 4 ounce round balls.

Place the burger on two pieces of parchment paper (top and bottom) and use a rolling pin to "smash" the burgers.

After repeating this step to create four burger patties, in the same large skillet used to caramelize the onion rings, on medium/high heat, add one teaspoon of butter to the pan.

When the butter begins to bubble place each smashed patty onto the griddle and season each side liberally with crushed/coarse salt and cracked black pepper.

It is important to note, the burger patties do not need to be tampered with while cooking. Only flip the patties once.

Once the burger patty is flipped, wait at least one minute before placing the sliced cheese on each patty. This cooking process should take 2-3 minutes per side depending on your desired temperature.

This step is very crucial and it's important to note, this burger is quite messy so have paper towels on hand!

After the burger patties have been removed from the cast iron skillet, place the caramelized onion rings back into the same pan the burger patties were prepared in on medium heat (this step only takes a few minutes).

Please note, you may need to remove some access grease from the pan, simply use a paper towel!

After the onion rounds have been placed into the pan, add a burger patty with cheese on top of each onion round. Allow a few minutes for the ingredients to mesh together and remove from the pan.

Simply stack each patty on top of each other making sure the onion rounds are on the outside of each patty, acting as a "bun" or cover. Be careful, the patties will be hot!