Cut cauliflower heads into small florets. Set oven to broil. Place half of the florets on a baking sheet and spray or brush with olive oil. Place baking sheet on middle rack of oven and broil until florets are roasted to a medium brown color, about 20 min. Meanwhile, in a large saucepan, bring remaining cauliflower, milk and half and half to a simmer over medium heat. Cover, reduce heat to low and continue to cook until florets are soft, about 20 min. Strain mixture through a colander, reserving both florets and liquid. Place roasted and boiled florets together in a food processor. Add one third of reserved liquid, Capitol Hill Seasoning, salt, white pepper, butter and lemon juice. Puree, adding more reserved liquid as needed to reach desired consistency.
Use puree as a bed for fish, chicken or beef, or as a dip for bread or vegetables.