Step 1

For the bacon jam: Cook the bacon in a large nonstick skillet over medium-high heat, stirring occasionally, until browned and crisp and the fat has rendered out. Allow to cool, then chop the bacon.

Step 2

In the same pan with the bacon drippings, add the onions and cook, stirring occasionally, until slightly softened. Add the brown sugar, vinegar and thyme; bring to a simmer. Reduce the heat to low and cook until the liquid is absorbed and the mixture has thickened to a jam-like consistency, about 20 minutes. Stir in the bacon; remove from the heat.

Step 3

For the burger: Divide the beef into 4 equal portions and form into burger patties. Sprinkle both sides of each patty with salt and pepper.

Step 4

Heat the oil in a pan or griddle over high heat. Cook the patties until golden brown and slightly charred on the first side, about 3 minutes. Flip over the patties and cook until golden brown and slightly charred on the second side or to the desired degree of doneness, about 4 minutes for medium-rare. Add 1 slice of American cheese and 1 slice of Cheddar to the top of each patty during the last minute of cooking, then top the pan with a basting cover or tent the patties with aluminum foil to melt the cheese.

Step 5

Coat the bottom of the buns with mayo. Put the patties on the mayo-coated buns and top with the arugula and bacon jam. Sandwich the burger together with the tops of the buns and serve immediately.