Place a steamer insert into a pot and fill with water to just below the bottom of the steamer. Bring water to a boil. Add cauliflower, cover, and steam until fork-tender, 10 to 15 minutes.

Remove cauliflower and steamer from the pot. Drain all water and return cauliflower to the empty pot. Add chives, parsley, garlic powder, and onion powder.

Set pot over medium-low heat. Mash cauliflower with a potato masher to the consistency of rice grains. Stir until excess moisture evaporates and the 'rice' appears fluffy, 5 to 7 minutes. Season with salt and pepper.