Vegetarian Moussaka - Filippo Berio

Ingredients

• 450g potatoes, thinly sliced
• 1 large aubergine
• 2 medium courgettes
• 6 tbsp Filippo Berio Classico Olive Oil
• 2 medium red onions, thickly sliced
• 2 garlic cloves, crushed
• 400g can chopped tomatoes
• 2 tbsp tomato purée
• Generous pinch of sugar
• ½ tsp dried oregano
• 100g feta cheese
• 1 large egg, beaten
• 150ml Greek style yoghurt
• 25g Parmesan cheese, freshly grated