Remove small side muscle from scallops and place scallops on a paper towel lined plate. Cover with another paper towel and place plate in fridge.
Heat 2 Tbs. clarified butter in a large pot over medium heat. Add onion and garlic and cook 3-5 minutes, or until softened but still pale. Add cauliflower, chicken stock, and cream, and bring mixture up to a simmer. Cover pot, reduce heat to medium-low, and cook for 7-9 minutes, or until cauliflower is tender. Remove cauliflower from pot with slotted spoon and transfer to a blender or a food processor. Return pot back to stove and raise heat to medium. Continue to cook for 8-10 minutes, or until liquid is reduced to just over 1/2 cup. Add liquid to blender or food processor and blend until smooth. Season to taste with salt.
Heat a large cast iron skillet over medium-high heat. Season scallops with Spicy Seafood Seasoning and add remaining clarified butter to skillet. When butter starts to smoke, gently lay scallops down in pan, making sure they are not touching. Cook, undisturbed, for about 1 1/2 minutes or until they develop a brown crust, then flip them and cook them for 1 1/2 minutes on the other side. Transfer cooked scallops to a paper towel lined plate.
Divide cauliflower purée between 4 plates or 4 shallow bowls. Lay 3 scallops on each plate and sprinkle with pistachios and chopped parsley. Serve immediately.
