Put the oil in a large pot over medium heat.

Once warm, add the onion, carrot, celery and some salt and pepper and cook, stirring occasionally, until the vegetables begin to soften, about 5 minutes.

Add the garlic in after 3 minutes of cooking the mirepoix.

Add the cauliflower, beer, stock, bay leaf and cayenne.

Bring to a boil, then adjust the heat so the mixture bubbles only slightly.

Cover and cook until the cauliflower is good and tender - about 10 to 15 minutes.

Remove and discard the bay leaf.

Purée the soup in batches in a blender until smooth.

Return to the pot.

Stir in the mustard and remaining salt and pepper.

In a bowl, toss together the cheddar cheese and cornstarch together and mix well.

Add the cheese mixture to the soup a handful at a time, stirring all the while, until it’s well incorporated and the soup is smooth.

Serve hot, garnished with the parsley.