Step 1

If you don’t already have caramelized onions then slice two large onions in half, peel and then in cut half moons. Heat a Tablespoon canola oil in skillet over medium high heat and cook onions for 20-25 minutes until they are a nice golden brown.  Stirring often.If the onions are browning too quickly turn heat down to medium.  If liquid evaporates add a little more oil or some water.  You want some kind of liquid so that the onions don’t burn.If using frozen caramelized onions, heat over medium heat.  Once warm remove to a platter and cover with foil.

Step 2

Use the same pan to cook the burgers and eventually the patty melts. Divide 1-pound ground beef, preferably grass fed, in fourths.Make an oval patty that’s a little larger than the bread itself since the meat will shrink when you cook it.Transfer to a parchment lined baking tray, sprinkle one side with salt and pepper and pop in the freezer for a few minutes, about 10-

Step 3

While freezing the patties, assemble the remaining ingredients and prepare any side dishes that you plan to serve.Griddle the patty melts on the stove over medium-high heat for 2-3 minutes per side for medium-rare. Flip when you see the juice rising to the top.  Remove when cooked.

Step 4

Place the cheddar cheese on a slice of bread, pile on some caramelized onions, then the cooked burger, and finally the Swiss cheese and another piece of rye bread.  Spread onerye piece with softened butter or mayonnaise.

Step 5

Turn heat down to medium.  Wipe out the pan with a paper towel.  Put the sandwich back in the pan with mayo side down and griddle like you would a grilled cheese.  Spread thetop with mayo and flip when bottom bread is golden, just enough to toast the bread and melt the cheese, about 3 minutes per side.