How to make it
In a medium sauce pan, add in butter and onion. Cook at medium heat for 2 minutes.
Stir in flour and cook mixture for an additional 2 minutes.
Stir in milk, Oyster Flavored Sauce and parsley. Mix well (mixture). Cook mixture until thickened.
In a 4 x 9 inch baking dish, mix in cauliflower, breadcrumbs, and mixture thoroughly.
Sprinkle parmesan cheese on top and bake at 350 degrees for 20 minutes or until mixture forms a crispy crust on top.