1. Preheat oven to 400^oF (205^oC). Line a baking sheet with parchment paper. 

2. While leaving the head of garlic intact, peel off the outermost papery layer. Cut the top of the head to reveal the cloves. Place the garlic onto a sheet of foil. Drizzle 1 tablespoon of olive oil onto it. Wrap the foil around the garlic. Set aside.

3. In a medium bowl, toss together the cauliflower florets, salt, and 2 tablespoons of olive oil until the cauliflower is coated. Place the cauliflower pieces onto the lined baking sheet. Put the foil-wrapped garlic next to the cauliflower.

4. Roast the cauliflower and garlic in the middle rack of the oven for 40 minutes. The garlic may take an additional 10 minutes longer or so to roast compared to the cauliflower, so you may have to leave it in the oven longer when you take the cauliflower out. The garlic should be soft and spreadable when done.

5. Put the roasted cauliflower into a food processor. Add in the remaining 2 tablespoons of olive oil, lemon juice, and black pepper, and squeeze the roasted garlic out of its skin into the food processor. Pulse for about 3-4 minutes, until the mixture is smooth and spreadable. If the mixture remains chunky after a few minutes of pulsing, add in an additional 1-2 tablespoons or water, or a little more oil into the mixture. 

6. Serve with the cut lemon wedges, and additional salt and pepper if desired. Note that the lemon juice will turn the purple mixture into a hot pink color.