One-pot mushroom & potato curry

INGREDIENTS

• 1 tbsp oil
• 1 onion , roughly chopped
• 1 large potato , chopped into small chunks
• 1 aubergine , trimmed and chopped into chunks
• 250g button mushrooms
• 2-4 tbsp curry paste (depending on how hot you like it)
• 150ml vegetable stock
• 400ml can reduced-fat coconut milk
• chopped coriander , to serve