This is a diner staple.  I have always found it best at 3 AM coming out of the bar.  Or at 11 AM when you skipped breakfast and don’t have any sales calls scheduled for the afternoon.  Either way it’s delicious.  I have updated it with an adobo mayo and sourdough.  I hope you like it.

2 6-oz beef patties

1 yellow onion, peeled

4 Swiss cheese slices

4 slices sourdough bread

1 tablespoon adobo sauce

4 oz mayo

Salt, pepper, garlic powder to taste

Olive oil to sauté onions

Butter for bread

Slice onions 1/8 inch thick

Heat pan to medium

Add olive oil

Add onions, turn frequently until golden

Sprinkle patties with seasoning

Heat cast iron skillet to medium

Add burger patties

Cook for 5 minutes per side

Remove patties from pan

Butter bread on one side

Mix adobo and mayonnaise; spread on the other side of bread

In cast iron pan, place bread butter side down

Add the hamburger patty

Add onions

Add 2 slices of cheese

Butter another slice of bread and top patty with butter side up

Brown bread on bottom (about 4 minutes)

Turn

Brown on other side

Serve with chips