Bring a pot of water to a boil. Cook cauliflower florets in the boiling water until they are extremely tender, about 10 minutes; drain in a colander. Put several paper towels on top of the cauliflower and use back of a big bowl to press down and squeeze as much liquid from the cauliflower as you can.
Mix Parmesan cheese, cream cheese, chicken soup base, roasted garlic, and butter in a bowl. Add cauliflower to the cheese mixture; beat with an electric hand mixer until creamy, about 3 minutes. Beat milk into the mixture until you get your desired texture. Season with salt and pepper.