To make the yogurt:

Line a colander with muslin or cheesecloth. Place the colander over a large mixing bowl. Place the yogurt in the colander, cover and refrigerate for at least 4 hours and up to overnight.

Discard the liquid in the bowl. Transfer the yogurt cheese to a small mixing bowl and use immediately or cover and refrigerate up to 4 days. (Yield: 2 cups)

To make the burgers:

Place the lamb, mint, basil, rosemary and fennel in a large bowl and, using your hands, mix until the ingredients are evenly incorporated.

Place the mixture on a work surface and divide into 4 balls of equal size. Form each into a patty about ¾ to 1 inch thick, tossing it back and forth between your hands. To ensure more even cooking, make a ½-inch indentation with your thumb in the center of the burger.

Handle the patties as little as possible; do not work more than necessary.

Prepare a grill to medium-high. When the coals are glowing red, after 15 to 20 minutes, cover with the grate. After 5 minutes, use a wire brush to thoroughly clean the grate. Brush the grate with oil. When the coals are covered with pale gray ash and you can leave your hand 5 inches above the fire for 2 to 3 seconds, the coals are ready.

Sprinkle both sides of the burgers with the salt and pepper. Place the burgers on the grate and grill until well seared on both sides, about 4 minutes for medium rare or 5 minutes for medium.

Transfer to pita bread pockets or a serving platter and serve immediately with yogurt and/or lemon quarters.

Alternatively, place a cast iron skillet over high heat and when it is hot but not smoking add the burgers to the dry pan. Cook until well seared on both sides, 8 to 10 minutes for medium rare or 10 to 12 minutes for medium.