Easy Vegetarian Moussaka

Name: Easy Vegetarian Moussaka
Ingredients: * 1 aubergine; * 300ml 1/2 pint vegetable stock; * 1 bay leaf; * 2 tbsp olive oil; * 1 small onion sliced; * 1 clove garlic minced; * 65g 2oz green lentil; * 112g 4oz mushroom sliced; * 200g 7oz canned chickpea drained and rinsed; * 200g 7oz canned chopped tomato; * 1 tbsp water; * 1 tsp dried oregano; * 1 tbsp fresh thyme; * 1 tbsp tomato puree; * topping;; * 1 egg; * 2 tbsp parmesan cheese grated; * 1/2 cup greek yogurt; * 1/4 tsp grated nutmeg; * salt and pepper to taste