For Cauliflower Bisque:

• Preheat oven to 425F.  Line a baking sheet with aluminum foil for easy clean up.
• Toss cauliflower florets with enough olive oil to lightly coat (~ 2 Tbsp) and sprinkle with salt (~ 1/4 tsp).
• Roast cauliflower uncovered ~ 12-15 minutes.  You want them soft with a little browned but not totally browned as that will affect soup color.  
• Remove cauliflower and reduce oven heat to 350F for croutons.
• Add butter to medium stock pot.  Add onions when butter is melted.  
• Cover and sweat onions over low heat (you want the onions translucent and not brown), for ~ 5-7 minutes or until soft.
• Add wine, cauliflower and enough water to cover the cauliflower by ¼" - ½ ".  Err on the side of less liquid as more can always be added later.
• Bring to a boil, reduce heat, and simmer covered until cauliflower is soft but not mushy (~ 10-15 minutes).
• Remove pot from heat.
• Immersion blend (or place in blender) the mixture until smooth.  You can also use a blender but will need to add the mixture to the blender in batches.  
• Stir in heavy whipping cream.  Add a little more water if you want a thinner consistency.  
• Add salt and pepper to taste.

For Croutons:

• Cut or pull bread apart into 1" chunks.  
• Toss in a large bowl with ~1-2 Tbsp extra virgin olive, salt, and pepper and bake on a lined baking sheet at 350F for ~ 7 -10 minutes or until golden and crunchy but not hard.
• Garnish soup with chopped parsley and croutons.