Mediterranean Lamb Burger

Place all of the ingredients except the oil in a large bowl and, using your hands, mix until just combined. Divide the meat into 4 equal portions. Shape each portion into an even 1/2-inch-thick patty that is about 1 inch wider in diameter than the kaiser rolls. Using your thumb, make a shallow 1-1/2-inch-wide indentation in the center of each patty (this helps the burgers cook more evenly).

Transfer the patties to a plate and refrigerate while you prepare the grill.

Heat a grill pan or outdoor grill to medium high (about 450°F to 550°F). When the grill is ready, use tongs to rub the grate with several layers of paper towels dipped in vegetable oil.

Place the patties on the grill indentation-side up, close the grill, and cook undisturbed (do not press down on the patties) until grill marks appear on the bottom, about 6 minutes. Using a spatula, flip the patties, close the grill, and cook until the juices run clear and the patties are firm to the touch, about 6 minutes more.

Spread about 1 tablespoon of the harissa mayonnaise on each top and bottom roll (2 tablespoons per burger—you will have some mayo leftover). Divide the feta among the bottom halves and top the feta with 4 cucumber slices per burger.

Place a lamb patty on each bottom half and top with a lettuce leaf. Close with the roll tops and serve immediately.