Honestly, you won’t need all of this lamb for six sandwiches, unless you really load them up with meat. But often you have to buy the whole leg, and why not have some leftovers for more sandwiches the next day? Don’t fret if the muscles separate when you trim the meat; just grill them separately. (Of course, the smaller ones will take less time to cook, so take care not to overdo them.)

This is a recipe where great ingredients will really shine, so if you have the option, choose a creamy French or Greek feta and tomatoes and arugula from a farmers market (or your own back-yard garden, if you can swing that).

Steps

1. Prep the lamb: If the lamb is rolled and tied, cut off and discard the twine and unroll the meat. With a sharp, thin-bladed knife, trim the fat, gristle, and silver skin, and cut small slits all over the meat. Fill the slits with the garlic slices, sprinkle the meat evenly with about 1 tablespoon salt, and set it aside for 1 hour.
2. Prep the sauce: Meanwhile, whisk the yogurt, minced garlic, 2 tablespoons olive oil, lemon juice, mint, and ¾ teaspoon salt and pepper to taste until smooth. Cover and refrigerate until ready to use. (Just before using, taste and adjust the seasoning with additional salt and pepper if necessary.)
3. Cook the peppers: Cut off the very tops and bottoms of the peppers and remove the cores and seeds. Cut the pepper bodies into wide, relatively flat planks, pressing to flatten if necessary. Prepare a two-level medium-hot fire in a charcoal grill or preheat a gas grill on high for 15 minutes. (If using gas, adjust the burners to medium-high.) Grill the pepper pieces skin-side down until the skin is charred and puffed, about 12 minutes. Place the charred peppers in a large heat-resistant bowl, cover, and steam to loosen the skins, about 10 minutes. Peel the peppers and slice into ½-inch-thick strips (you should have about 1½ cups). Toss the pepper strips with 1 tablespoon olive oil, ¼ teaspoon salt, and pepper to taste, and set aside.
4. Cook the lamb: Dry the lamb well with paper towels, rub with the remaining olive oil, and season liberally with pepper. Grill the lamb until the exterior is well-browned and the center is still pink and registers about 125 degrees for medium-rare, about 25 minutes (less time for small pieces), turning and moving to the cooler area on the grill as necessary to prevent scorching. (If using a gas grill, adjust the burners to medium and grill with the cover down.) Transfer the lamb to a platter or cutting board, tent loosely with foil, and rest 20 minutes. Slice very thin, against the grain and on the bias.
5. Assemble the sandwiches: Spread each sheet of mountain bread with about ⅓ cup yogurt sauce and top with a few slices of lamb, about ¼ cup each grilled peppers and feta, ⅓ cup chopped tomatoes, and a portion of arugula. Fold the bottom 1½ inches of the bread sheet up over the fillings, then fold one edge over the fillings and roll, tucking and tightening as you go. Place the rolled sandwiches seam sides down on plates and serve at once.