Before we get into it, for the authentic Juicy Lucy experience, using American cheese with its supreme melting abilities is non-negotiable. Also, half-sour pickles make an excellent topping if you can find them in your local stores, adding a fresh and crunchy touch. These are readily found in the refrigerated aisles, but not exactly essential.

The Juicy Lucy story traces back to Matt's Bar in Minneapolis, Minnesota. According to tales from the establishment, a patron wanted a new twist on the regular cheeseburger and requested a cheese slice sandwiched between two patties. Upon biting into it, he declared “that's one juicy Lucy!”, thus the name. Its initial misspelling in the menu as 'Jucy Lucy' remained as the bar owners decided to retain the typographical error intact.

For the onions, a tip to keep them from getting charred while achieving a rich caramel color is deglazing the pan with water. Do bear in mind the cheese placement is crucial to prevent a cheesy disaster – it must only be placed at the center of the patty, then reshape and sculpt the burger ensuring it is completely sealed, preventing any unforeseen cheese leaks during grilling.

In addition to the above, caramelized onions can be prepped three days prior, making sure they are tightly sealed in an airtight container and refrigerated. In the same vein, the cheese-stuffed burgers can also be readied in advance on a parchment-lined baking sheet and refrigerated for up to a day, remembering to cover them.

The preparation process commences with setting 2 tablespoons of canola oil to heat in a skillet over medium-high heat. The thinly sliced large sweet onion, along with half a teaspoon of salt, is added and cooked till sweat is visible, usually around 2 minutes. The heat is reduced to medium, stirring occasionally, until the onion achieves a silky and deeply browned look, after approximately 30 minutes. Replenish the water in cooking as needed, at 2 tablespoons at a time, if the burning starts. The onions are then set aside.

While onions are being attended to, divide the ground chuck into portions, flatten each one on a parchment paper. Next comes positioning each cheese square directly at the center of 4 patties. The remaining patties cover the cheese-topped patties, crimped at edges, forming a 4-inch patty that needs to be slightly flattened as well.

For the next step, heat your skillet at high, then season patties with pepper and the remaining salt before adding some more oil for a proper coating. Now it's grill time – ensure your patties are nicely browned on both sides for the perfect medium-rare to medium. Removed from the skillet, the burgers are covered with aluminum foil to keep warm.

Finally, toast the buns faced down in the residual fat in the skillet at low heat, place pickle slices on the bottom buns if desired, top it with your stuffed burgers and caramelized onions, and serve immediately.