1.Preheat oven to 180°C/160°C fan-forced.
2.Combine lentils and bay leaf in small saucepan, cover with water, bring to the boil. Reduce heat, simmer, covered, 10 minutes, or until lentils are almost tender. Drain and 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.
4.Preheat grill. Sprinkle lentil mixture with cheese. Place under grill, 3 minutes, or until cheese browns lightly. Sprinkle with chives to serve.