Chunky leek and potato soup

Olive oil spray 1 large onion, thinly sliced 2 medium leeks, thinly sliced 2 garlic cloves, finely chopped 2 medium potatoes, peeled and cubed 2 x 500ml Cooks’ Ingredients vegetable stock 4 tbsp half-fat crème fraîche 2 tbsp chopped chives