Wash cauliflower and cut off flowerettes. Place them in a medium saucepan and cook in chicken stock on medium-high heat setting until tender. Let them cool. Set aside.

Melt butter in large saucepan. Add onion and cook until limp. Mix in flour and pepper. Add milk. Heat on medium heat setting until the mixture boils and thickens. Don't rush this by increasing heat - the milk will burn.

Using 2 knives, chop the cooked cauliflower into small pieces, and add it (including the chicken stock) to the milk mixture.

Adjust flavour with salt if necessary.

Serve in soup bowl, topped with grated cheddar cheese.