1.Preheat oven to moderate 180°C (160°C fan-forced).
2.Combine lentils and bay leaf in small saucepan, cover with water; bring to a boil. Reduce heat; simmer, covered, about 10 minutes or until lentils are almost tender. drain; discard bay leaf.
3.Combine lentils, leek, juice, garlic and stock in 3-cup (750ml) ovenproof dish. Bake, covered, about 40 minutes or until the leek is tender, stirring halfway through cooking.
5.Sprinkle lentil mixture with cheese; place under grill about 3 minutes or until cheese browns lightly. Sprinkle with chives.