I found this recipe at a blog called From Pasta to Paleo (http://frompastatopaleo.com/2013/07/25/smashed-garlic-cauliflower) and it is awesome!
1 head cauliflower – tough stem removed, remainder cut into florets
3 cloves garlic
2 tbsp grassfed butter, ghee or olive oil
salt & pepper, to taste
Steam one head of cauliflower and 3 peeled garlic cloves until it is soft (softer than if you were eating it as is) about 10-12 minutes. Remove cauliflower and garlic and place in food processor with butter, salt and pepper. Puree until smooth. Boom–a delicious substitute for mashed potatoes! I was amazed by how good this was!