Even mashed potato lovers agree that cauliflower makes a great, healthy, alternative.
Chop the cauliflower into small pieces.
Steam cauliflower, garlic and leeks until completely tender, about 20 to 30 minutes.
Use a food processor or a hand mixer to puree the vegetables until the texture resembles mashed potatoes.
Add a little hot water if vegetables seem dry.
Stir in butter and pepper to taste. Serve.