Slice the onion- you don't want the slices too thick, or too thin.
Add a tablespoon of butter to a skillet over medium-low heat.
Add the onions along with a good-sized splash of Worcestershire sauce.
Stir the onions and let them slowly cook until they are tender, yet still have just a bit of crunch.
A few minutes before the onions finish, add a pat of butter to a clean skillet and set the heat to medium-low.
While the butter is melting, prepare the Ball Park® patties.
Add a slice of rye bread in the skillet with the now-melted butter.
Swirl it around so the outside surface really soaks up the butter.
Now lay a piece of Swiss cheese on top.
Next add a patty.
Add a scoop of the sauteed onions on top of the patty
Followed by another slice of Swiss cheese
Top with another slice of rye.
Let the first side turn a nice golden brown, then flip it to the other side, adding a tad more butter.
Now let the other side get golden brown and the cheese completely melt.
Remove from pan, pace it on a plate and slice it in half.