With the rack in the middle position, preheat the oven to 350°F (180°C).
In a bowl, combine the salt, brown sugar, coriander seeds, red pepper flakes and peppercorn. Coat the lamb with the spice mix.
In a large skillet over medium-high heat, brown the lamb in the oil. Set aside in a large roasting pan. In the same skillet, coat the vegetables with the pan drippings and place around the leg of lamb.
Bake for about 1 hour and 10 minutes for rare doneness or until a thermometer inserted into the centre of the meat, without touching the bone, reads 122°F (50°C). Set the lamb aside on a plate, cover with aluminum foil and let rest for 15 to 20 minutes or until the internal temperature reaches 135°F (57°C). Remove the twine. Continue cooking the vegetables while the meat rests.
In a food processor, chop the herbs, green onion, garlic and chili pepper. Add the oil and vinegar. Season with salt and pepper. Pulse until just coarse. Set aside in a bowl.
Slice the leg of lamb. On a serving plate, place the meat and vegetables. Dress with half of the sauce and serve with the remaining sauce.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.