Step 1

In a frying pan heat olive oil over medium heat and sauté the chopped onion until it becomes translucent.

Step 2

In a large bowl, combine the ground beef, sautéed onion, Worcestershire sauce, salt, and pepper.

Step 3

Form the beef into 6 fairly thin patties. (About 5 inches in diameter) They will shrink and thicken as they cook.

Step 4

Grill each patty on medium-high heat, about 5 minutes per side.

Step 5

Assemble your burger according to your liking. I like to spread a little mayonnaise and Dijon mustard on each bun, then stack lettuce, onions, tomatoes, pickles, patty, sautéed mushrooms, and Havarti cheese.