Cauliflower Soup with Mushrooms

Ingredients

• 1 tbsp olive oil
• 125g chestnut mushrooms, sliced
• 1 1/2 cloves garlic, minced
• 1 tbsp fresh rosemary, finely chopped
• 50g walnuts, chopped
• 1 tbsp smoked paprika
• 1 medium cauliflower (680g)
• 120ml water
• 240g double cream
• 25g strong cheddar cheese, grated
• 2 tbsp butter (30g)
• Salt, to taste