Finely grate 1 tablespoon zest from the lemons and then squeeze them to yield 3 tablespoons juice. Combine the zest and juice with the mint, garlic, 2 teaspoons salt, and 1 teaspoon pepper in a food processor. Pulse a few times and then with the motor running, add the oil. Reserve 1/4 cup and refrigerate.

Trim the fat on the lamb racks to a 1/4-inch-thick layer. Poke holes all over the lamb with a fork to help the marinade penetrate. Lightly score the fat layer about 1/16 inch deep in a 1/2-inch diamond pattern. Arrange the racks, fat side up, in a 9x13-inch baking dish, overlapping the bones if necessary to fit the racks in the dish. Brush the remaining salsa verde all over the racks. Cover and refrigerate for at least 8 hours and up to 24 hours.

Heat the oven to 425 degrees F. Take the lamb out of the fridge and arrange the racks fat side up in a large roasting pan (or rimmed baking sheet)--they should fit in one layer. Brush the top and sides of each rack with 1 tablespoon of the reserved salsa verde. Roast for 15 minutes. Brush with 1 tablespoon more of the salsa verde and continue to roast to an internal temperature of 130 degrees to 135 degrees F for medium rare, an additional 15 to 20 minutes. Let the meat rest for 5 minutes before carving into chops. Drizzle the remaining salsa verde over each serving.