I was very pleased with making this celeriac mash in my blender. It is very similar to making mashed potatoes. You peel the celery root and cut it into cubes. Then you boil it with a tablespoon of salt for 20-30 minutes until it is fork tender. Transfer the celeriac cubes into the blender with 1/4 cup of milk, 1/4 cup of water, a handful of shredded cheese, salt and pepper to taste, a pinch of your favourite herb and a tablespoon of butter. Puree it in the blender.
This is a great low carb dish. Of course if you don't like the taste of celery you won't like celery root.