Remove the lamb from the refrigerator 30 minutes before cooking.
Preheat the oven to 180°C.
To make the stuffing, heat the oil and butter in a medium frying pan, then add the onion and sauté until lightly golden and starting to soften (about 8 minutes). Set aside in a bowl.
Place the sundried tomatoes in a small food processor with the garlic, then process to a coarse purée, add to the onions.
Add the chopped herbs, Italian seasoning, breadcrumbs and egg. Mix to combine.
Take the meat from the string wrap, spread over the stuffing and carefully roll up, fastening the lamb with butchers/kitchen string.
Rub lamb with a little oil and place in a small roasting dish, cook for 40 minutes medium-pink meat. Or use a good meat thermometer and check for a temperature of 55°C–60°C. Remove lamb from the oven and let it rest, loosely covered, for about 15 minutes. Remove the string and sprinkle with flake salt