Aubergine and courgette Parmesan bake

Ingredients

• large aubergines , cut into 1cm discs
• large courgettes, cut into 0.5cm strips
• olive oil
• onion, finely chopped
• red pepper, finely chopped
• garlic, crushed
• heaped tsp dried oregano
• x 400g can chopped tomatoes
• Parmesan cheese, finely grated
• reduced-fat mozzarella, thinly sliced