Meanwhile, wash cauliflower. Cut out core and discard.
Break cauliflower into florets about 2 inches in diameter and toss into boiling water. Water should just cover florets. (To break large florets into smaller ones, cut through stems at bottom and break upward into smaller pieces.)
Bring back to a boil. Then turn heat down to medium and simmer for 3 to 4 minutes. Florets should remain firm, so don’t over-cook.
Drain water and set cauliflower aside to cool.
Heat oven to 350 degrees. Spray or oil a baking dish.
To make sauce, melt butter in a saucepan on low heat. Add flour and stir until combined well. Pour in coconut milk and raise heat to medium/high, stirring constantly until well combined. Add salt, pepper and Italian seasonings and simmer on low heat, 6 to 8 minutes until sauce thickens. Set aside.
Arrange florets with stem sides down in prepared baking dish. Sprinkle chopped peppers and seeds or nuts, if desired, over florets.
Spoon sauce over top, moving florets if necessary to allow sauce to seep around and down into dish. Let rest 5 minutes.
Sprinkle with cheese or Bread Crumb Topping, if desired.
Place in preheated oven and bake 30 to 35 minutes or until tender. Cover if cheese darkens too quickly.