Preheat grill to medium-high heat. Clean and oil grill, if needed.
Divide the meat into 4 large balls, then shape into 1/2 to 3/4-inch thick patties slightly larger than the buns with your hands, taking care not to overwork the meat. Make a shallow depression in the center of each burger for more even cooking.
1 1/2 pounds 80/20 or 85/15 ground beef
Season the burgers with the salt and pepper on both sides.
1 1/2 teaspoons kosher salt, 1 1/2 teaspoons freshly ground black pepper
Place the burgers on the grill directly over the flames or heat source and cook for 4-6 minutes without moving. Flip and grill on the other side for another 4-6 minutes until the burgers reach your desired degree of doneness. Divide the cheese between the burgers during last two minutes of grilling and close the lid so it can melt.
1 cup Gruyere or Havarti cheese
While the burgers are grilling, stir the garlic into the melted butter. Brush the garlic butter onto the cut sides of the buns, then place them buttered side down on the grill until toasted, about 1 minute.
2 cloves garlic, 4 Tablespoons salted butter, 4 brioche buns
To assemble the burgers, spread a generous amount of the bacon jam on the bottom bun. Top with a thick slice of tomato, followed by the burger patty, more bacon jam, and a generous handful of arugula. Set the top bun in place and serve immediately. 1 to 1 1/2 cups bacon jam, 4 thick slices of ripe tomatoes, 3-4 cups baby arugula