Remove the leaves and stem from the head of cauliflower and then trim the cauliflower into bite-size florets.
Add them to a large pot of boiling salted water and cook for 5 minutes.
Drain the cooked cauliflower very well before transferring to a baking dish.
Pour in the mornay sauce and mix until completely coated and mixed in.
Evenly sprinkle the breadcrumbs over top, covering the cheesy cauliflower.
Bake at 400° for 20 to 25 minutes or until browned on top and especially around the outside of the inside of the baking dish.
Add an optional garnish of parsley and serve.