Fill a bowl with water and add the cauliflower florets and lemon juice. Set aside.
Using a large frying pan over medium heat, warm the olive oil. Add the bread slices and fry, turning once, until golden brown on both sides. Remove from the pan, break into pieces, and place in a blender or food processor.
Add the paprika to the oil remaining in the pan. Over low heat, cook the paprika for 2 minutes to release the fragrance. Add the 2 cups of water and bring to a boil. Drain the cauliflower and add it to the pan. Season with salt and cook, uncovered, until the cauliflower is tender, 10 - 15 minutes.
Meanwhile, add the garlic, pine nuts, and parsley to the blender or food processor and pulse until well crushed. When the cauliflower is tender, add about 1/4 cup of the cauliflower cooking water, pulse once, and then transfer the mixture to the frying pan. Stir to mix and cook for 5 minutes over low heat to blend the flavors.
Season to taste and transfer to a serving bowl. Serve hot.