Line 1 large and 1 medium oven tray with baking paper.
Using a sharp knife, cut 1cm deep slashes into the lamb. In a small jug, combine garlic, oil and chopped herbs. Season to taste. Massage herb mixture over leg, rubbing into slashes. Let lamb marinate for several hours.
Place leg onto smaller tray, season surface with extra salt and pepper and cook for 1 hour. Place the vegetables into the larger tray, mixing through the olive oil, oregano, and salt and pepper. Bake with lamb, allowing both to cook for a further 45-50 minutes.
Toss vegetables halfway through cooking.
When ready vegetables should be tender, and slightly golden brown.
Test lamb to see if cooked to your liking, increase cooking time by 10 minutes if you prefer a well done lamb.
Before carving meat, cover with foil and allow to sit in warm place for 15 minutes.
Slice meat and serve alongside roasted vegetables, using leftover cooking juices from the pan.