Break the cauliflower into florets and either steam or boil them for 8 to 10 minutes until they become completely soft and easily pierced with a fork.
Alternatively, use a pressure cooker by adding 1/2 cup of water to the bottom and placing the cauliflower florets on a steamer insert. Cook under high pressure for 2 minutes.
Once cooked, allow the cauliflower to drain and cool slightly. Then, wrap it in a clean kitchen towel and squeeze out as much excess moisture as possible. If short on time, tongs or rubber gloves can be used to press out the liquid while the cauliflower is still warm—just be cautious of the heat.
For a rustic, chunkier texture, mash the drained cauliflower with the butter, sour cream, cheddar cheese, salt, and black pepper using a fork or potato masher.
For a silky-smooth consistency, blend the cauliflower in a food processor along with the butter, sour cream, cheddar cheese, salt, and black pepper. Process for about one minute until creamy and uniform.
Stir in the chopped chives or use them as a garnish for a fresh, flavorful finish. Serve warm and enjoy!