Cut cauliflower into florets, discard core and leaves.
Place florets in a pot, cover with water, add salt.
Cook on medium heat until florets are soft.
Drain cauliflower over a colander, return florets into the pot.
Set pot over medium-low heat, mash with a fork or potato masher and cook, stirring constantly, for at least 3 minutes, to get any remaining moisture out.
Add sour cream (2 tablespoons at a time), salt and pepper, butter and mash until desired consistency is reached.
Serve garnished with chopped parsley or chives.
Notes
One serving is 1 cup of mashed cauliflower.To freeze: mash the cauliflower without the sour cream, cool it completely, then place in a ziploc bag. Make sure you get all of the air out of the bag before sealing. I think it can be frozen for up to 3 months. Do not forget to mark the bag with contents and the date.