Preheat oven to 350. Using a mortar and pestle, mash the garlic and salt into a paste. Gradually mix in the olive oil. Stir in the herbs and pepper.
Fit the lamb into a roasting pan big enough to contain it. Smear it thoroughly with the paste, and place it ribs-side down in pan. Cover tightly with foil, and roast until it reaches an internal temperature of 170 degrees, 2 to 3 hours, depending on size of breast. Meat should be wobbly but not falling apart. Allow to cool, then cover and rest in the refrigerator overnight.
The next day, prepare the sauce. Whisk 1 tablespoon of olive oil into the yogurt. Then the lemon juice. Stir in mint, lemon zest and salt. Before serving, drizzle sauce with remaining tablespoon of olive oil and sprinkle with pepper and a pinch of paprika to taste.
Light your grill, or place a large skillet over medium-high heat. Cut the breast and ribs away from the bone that runs lengthwise between them. Cut the breast into half-inch slices that resemble thick-cut bacon, and separate the ribs. Reserve fat from the roasting pan. Cook a few pieces of lamb at a time on fairly high heat, until browned and crispy on both sides, approximately 4 to 6 minutes.
Brush the onions with some of the lamb fat. Place them on the grill or on a pan under a preheated broiler. Cook them, turning once or twice, until flimsy and slightly charred. Remove them to a large bowl and dress with the vinegar and salt and pepper to taste.
YIELD 4-6 servings.
Source: NY Times