How to Make It
In a small saucepan, combine the capers, raisins and 3/4 cup of water. Simmer over moderately low heat until the raisins are plump, 10 to 15 minutes; do not boil. Transfer to a blender and puree. With the blender on, add 6 tablespoons of the butter, 1 tablespoon at a time, until incorporated. Add the sherry vinegar to the caper-raisin sauce and season with salt and pepper.
In a large skillet, melt 1 tablespoon of the butter in 1 tablespoon of the oil. Add half of the cauliflower and cook over moderately high heat, turning, until crisp-tender, 5 minutes. Transfer to a rimmed plate, then repeat with 1 tablespoon each of the butter and oil and the remaining cauliflower. Let the skillet cool for 2 minutes. Add 1/2 cup of water and cook over moderate heat, scraping up any browned bits, 2 minutes. Stir in the parsley and pour the pan sauce over the cauliflower; keep warm.
In a nonstick skillet, melt 1 tablespoon of the butter in 1 tablespoon of the oil. Season the scallops with salt and pepper and add half to the skillet. Cook over moderately high heat, without turning, until the scallops are golden brown on the bottom, 3 minutes; transfer to a plate. Repeat with the remaining 1 tablespoon each of butter and oil and the scallops. Rewarm the caper-raisin sauce.
Spoon the raisin sauce onto 4 plates. Top with the scallops, browned side up. Arrange a cauliflower slice on each scallop, spoon a little of the pan sauce over and garnish with the nutmeg. Serve at once.