Remove lamb racks from the refrigerator 30 minutes before cooking to bring to room temperature. Pat dry with paper towels and rub with 2 tablespoons olive oil, sea salt, and black pepper.

Prepare the mint pesto by adding mint leaves, parsley, pine nuts, garlic, parmesan, and salt to a food processor. Pulse while slowly drizzling in the extra virgin olive oil until smooth. Stir in the lemon juice and set aside.

Preheat your barbecue grill to high heat on one side and medium heat on the other, creating two cooking zones.

Toss the spring onions with 1 tablespoon olive oil and a pinch of salt. Set aside.

Sear the lamb racks fat-side down on the high heat zone for 3-4 minutes until golden and crispy. Turn and sear all other sides for 1-2 minutes each.

Move the lamb racks to the medium heat zone, positioning them bone-side down. Close the lid and grill for 12-15 minutes until the internal temperature reaches 63°C for medium-rare or 68°C for medium, using a meat thermometer to check the thickest part.

During the last 5 minutes of cooking, place the spring onions on the high heat zone and grill for 2-3 minutes per side until charred and slightly softened.

Transfer the lamb racks to a cutting board, tent loosely with foil, and rest for 5-8 minutes. The internal temperature will rise approximately 3-5°C during resting.

Slice the lamb racks between the bones into individual cutlets. Arrange on a serving platter with the charred spring onions and drizzle generously with mint pesto. Serve immediately with remaining pesto on the side.