Conchiglioni stuffed with vegetables, sun-dried tomatoes & ricotta

Ingredients

• 32 conchiglioni
• 1 onion
• 1 courgette
• 1 tomato
• 2 carrots
• 1 pepper
• 1 handful sun-dried tomatoes
• 2.5 dl tomato sauce
• 3 tablespoons ricotta cheese
• 60 g grated Parmesan cheese
• olive oil
• ½ vegetable stock cube
• 1 tsp oregano
• salt and pepper