Cream of cauliflower soup with sautéed wild mushrooms

INGREDIENTS

• 1 large cauliflower (about 1.3kg/3lb), stalks discarded and florets chopped
• 1 large potato , peeled and chopped into large chunks
• 1 medium onion , chopped
• 25g butter
• 4 tbsp olive oil
• 1.2l light chicken or vegetable stock
• 600ml full-fat milk
• 142ml carton double cream
• 250g wild mushrooms - choose from ceps, girolles (chanterelles), morels (either a mixture or just one type)
• 1-2 tbsp finely snipped chives