Trim cauliflower and cut into florets.

Heat butter in heavy pan; add onion and leek, cover and cook gently 3 to 4 minutes (until vegetables start to soften). Do not brown.

Add cauliflower (save a few for garnish) and cook gently for 5 to 6 minutes. Pour in stock or water, bring to the boil, reduce heat and simmer for 20 to 30 minutes or until cauliflower is tender.

Purée soup in blender until smooth. Return to pan and bring to the boil again.

In a separate bowl, whisk together egg yolks, cream and Sharp Canadian Cheddar (or Canadian Brick or Canadian Farmer's cheese).

Whisk 1/3 to 1/2 cup (80 mL to 125 mL) of the hot soup into the egg mixture, then stir it back into the remaining soup; do not let it boil again.

Season with salt, pepper and nutmeg.

Serve with crunchy cauliflower florets as garnish and lots of crusty bread and butter.