Slow cooker vegetarian moussaka

Ingredients

• 1 large aubergine, diced
• Light cooking spray oil
• 1 medium onion, diced
• 1–2 cloves garlic, finely diced
• 2 peppers (colour of your choice), deseeded and cut into chunks
• 2 large courgettes, diced
• 120g dried puy lentils, rinsed
• 500g passata
• 200ml reduced-salt vegetable stock
• Small handful fresh rosemary (leaves only) or 1⁄2 teaspoon dried rosemary
• Freshly ground black pepper, to taste
• 225g fat-free Greek-style yoghurt
• 3 medium eggs, lightly beaten
• 1 teaspoon nutmeg, freshly grated
• 25g parmesan cheese, grated (or vegetarian equivalent)