Nibblous | cauliflower cheese soup

Ingredients

• 50g butter
• 1 medium onion, peeled and roughly chopped
• 2 cloves garlic, peeled and crushed
• 2 small (not baby) cauliflowers, cut into florets
• 2 bay leaves
• 200g creme fraiche
• 1 heaped tablespoon grain mustard
• 125g gruyere, cantal or strong cheddar, coarsely grated
• salt and pepper