Ok, this is from my AWW Slow Cooker recipe book. It's delish!

30g butter
1 tablespoon olive oil
1 large leek (500g), sliced thinly
1.8kg piece pumpkin, chopped coarsely
1 large potato (300g), chopped coarsely
3 cups (750ml) chicken stock
3 cups (750ml) water
1/2 cup (125ml) pouring cream
1 tablespoon finely chopped fresh chives

1. Heat butter and oil in large frying pan; cook leek, stirring, until soft.
2. Combine leek, pumpkin, potato, stock, and the water in 4.5 litre slow cooker. Cook, covered, on low, 6 hours.
3. Cool soup 10 minutes. Blend or process soup in small batches, until smooth. Return soup to cooker. Cook, covered, on high, about 20 minutes or until hot. Stir in 1/3 cup cream. Season to taste.
4. Serve soup topped with remaining cream and chives.