Preheat oven to 375F.
Remove core and stem of cauliflower and pull apart the florets. Place them and the whole onion in its jacket on a parchment covered baking sheet. Drizzle sparingly with EVOO and season to taste. Mix with your hands. Bake for 20-30min until fork tender. Turning over to colour evenly after 10-15min. Season again sparingly.
In a small oven proof dish or baking sheet mix crumbs with 1 tbsp of the pecorino cheese and 1tbsp. oil. Stir to combine and bake for 10min. *watch carefully, do not burn* This is the crunchy topping for the cauliflower.
Toss after 5 min. to brown evenly.
Squeeze cooked onion from skin. Add to processor along with, cauliflower, broth, ricotta, pecorino and blend to a smooth consistency. This should still be hot. (It can be cooled to room temperature and reheated when needed, within 1-2 hrs. )
Sprinkle crumbs over cauliflower for each individual serving or spread cauliflower into a casserole dish and sprinkle crumble over top serving family style.