This is a delicious mashed potato replacement. Believe it or not, my family requests this over traditional mashed potatoes for Thanksgiving, despite not being keto.
Combine the cauliflower and butter in a large pot and pour chicken stock over.
Bring to a boil, uncovered and cook until there is almost no liquid left and the cauliflower is just beginning to caramelize (this is key for a good texture - too much liquid results in a runny puree), about 30 minutes on medium-high heat.
Using an immersion blender, puree the now soft cauliflower until completely smooth. You can also transfer everything to a traditional blender and puree.
Add salt and pepper to taste.
Notes
For a special twist, add a package of Boursin garlic and herb cheese while pureeing.Adding one celery root (cube and cook it alongside the cauliflower) is another tasty addition but it increases the carbohydrate count from 6 to 12g per serving.