Preheat the grill to medium-high heat, about 450-500 F.

Add the ground beef to a large bowl along with the salt and pepper and work the mixture with your hands to combine.

Form the mixture into 6 1/2 inch thick patties (a little over 5 ounces each), then brush them with the oil.

Place the patties on the grill oil side-down, then close the grill lid and cook for 3-4 minutes, until the patties are browned on the bottom and have dark grill marks.

For medium-rare burgers: cook for an additional 2 minutes (about 6 minutes total), until the patties are just browned or the temperature registers 140 F.

For medium burgers: cook patties for an additional 3-4 minutes (about 7-8 minutes total), until the patties are browned or the temperature registers 145 F.

For medium-well burgers: cook patties for an additional 4-5 minutes (about 8-9 minutes total), until the patties are browned and have deep grill marks, or the temperature registers 150 F.

Remove the patties from the grill, then assemble.

To assemble the burgers: smear the buns with mayonnaise or other condiments of choice, then place the hamburger patty on the bottom bun and top with the tomato, lettuce, and top bun, and serve.