BBC Food - Recipes - Pumpkin stew with sour cream

Ingredients

• 40g/1½oz butter
• 2 onions , chopped
• 1 carrot , chopped
• 1 stick celery , chopped
• 3 sprigs rosemary
• 2 bay leaves
• 1 clove garlic , chopped
• 400g/14oz lentils
• 1.2litres/2pints 2fl oz vegetable stock
• 600g/1lb 5oz assorted pumpkin or squash (total chopped weight)
• small bunch parsley , chopped
• 2 tbsp red wine vinegar
• 4 tbsp sour cream